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BUREAU OF MINES 
INFORMATION CIRCULAR/1988 



Characterization of the 1986 
Sand and Gravel Mining 
Workforce 

By Shail J. Butani and Ann M. Bartholomew 



UNITED STATES DEPARTMENT OF THE INTERIOR 



Information Circular 9203 



Characterization of the 1986 
Sand and Gravel Mining 
Workforce 

By Shail J. Butani and Ann M. Bartholomew 



UNITED STATES DEPARTMENT OF THE INTERIOR 
Donald Paul Hodel, Secretary 

BUREAU OF MINES 
T S Ary, Director 











aj£ 




Library of Congress Cataloging in Publication Data: 



Butani, Shail J. 

Characterization of the 1986 sand and gravel mining workforce. 

(Bureau of Mines information circular, 9203) 

Bibliography: p. 7. 

Supt. of Docs, no.: I 28.27:9203. 

1. Sand and gravel industry— United States— Employees. I. Bartholomew, Ann M. 
II. Title. III. Series: Information circular (United States. Bureau of Mines); 9203. 

TN295.U4 [HD8039.S252U6] 622 s [331.7'622362'0973] 88-600274 



CONTENTS 



Page 

Abstract 1 

Introduction 2 

Acknowledgments 2 

Survey methodology 2 

Population 2 

Sample 3 

Data collection 3 

Data coding, entering, and editing 3 

Estimation procedures 3 

Grouping of characteristics 4 

Job title and principal equipment operated 4 

Employment size class 4 

Present job, present company, and total mining 

experience 4 

Job-related training during last 2 years 4 

Age 4 

Reliability of estimates 4 

Validation of estimates 5 



Page 

Summary of major findings 5 

Application of data for injury analyses 7 

Recommendations for future work 7 

References 7 

Appendix A.— Sand and gravel mining industry job title 

grouping 8 

Appendix B.— Sand and gravel mining industry equip- 
ment operated grouping 11 

Appendix C. — Estimation procedures 13 

Appendix D.— Reliability of estimates: random group 

variance technique 14 

Appendix E.— Sand and gravel mining 1986 workforce 

estimates 15 

Appendix F.— Mining industry population survey letters 

and questionnaire '. . 37 



ILLUSTRATIONS 

1. Percentage of 1986 sand and gravel mining workforce with at least a high school diploma, by age 6 

2. Percentage of 1986 sand and gravel mining workforce with at least a high school diploma, by sex 6 

3. Percentage of 1986 sand and gravel mining workforce with at least a high school diploma, by race 6 



TABLES 



1 . Population and injury statistics for 1986 sand and gravel mining sector 2 

Sand and gravel mining 1986 workforce estimates — 

E-l . Job title, by employment size class 15 

E-2. Principal equipment operated, by employment size class 15 

E-3. Work location at mine, by employment size class 15 

E-4. Experience at job, company, and mining, by employment size class 16 

E-5. Training received, by employment size class 16 

E-6. Age distribution, by employment size class 17 

E-7. Sex, race, and education, by employment size class 17 

E-8. Job title, by principal equipment operated 18 

E-9. Job title, by work location at mine 19 

E-10. Job title, by years of experience at job 20 

E-l 1 . Job title, by years of experience at company 20 

E-12. Job title, by years of mining experience 21 

E-13. Job title, by hours of training received in last 2 years 21 

E- 14. Job title, by years of age 22 

E-15. Job title, by sex 22 

E-16. Job title, by race 23 

E- 1 7 . Job title, by education 23 

E-l 8. Principal equipment operated, by years of experience at job 24 

E-19. Principal equipment operated, by hours of training received in last 2 years 24 

E-20. Principal equipment operated, by years of age 25 

E-21 . Principal equipment operated, by sex 25 

E-22. Principal equipment operated, by race 26 

E-23. Principal equipment operated, by education 26 

E-24. Job, company, and mining experience, by work location \ 27 

E-25. Training received, by work location 27 

E-26. Age distribution, by work location 28 

E-27. Sex, race, and education, by work location 28 



11 



TABLES — Continued 

Page 

E-28. Experience at job, by hours of training received in last 2 years 29 

E-29. Experience at job, by years of age 29 

E-30. Experience at job, by sex 30 

E-3 1 . Experience at job, by race 30 

E-32. Experience at job, by education 30 

E-33. Experience at company, by hours of training received in last 2 years 31 

E-34. Experience at company, by years of age 31 

E-35. Experience at company, by sex 32 

E-36. Experience at company, by race 32 

E-37. Experience at company, by education 32 

E-38. Age, by education 33 

E-39. Age, race, and education, by sex 33 

E-40. Age and education, by race 34 

Number of workers and coefficient of variation — 

E-41 . By employment size class 34 

E-42. By job title 34 

E-43. By principal equipment operated 35 

E-44. By work location 35 

E-45. By experience at job, company, and mining 35 

E-46. By training received 35 

E-47. By age 36 

E-48. By sex, race, and education 36 



UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT 


h 


hour 


pet 


percent 


yr 


year 







CHARACTERIZATION OF THE 1986 SAND AND GRAVEL MINING WORKFORCE 



By Shail J. Butani 1 and Ann M. Bartholomew 2 



ABSTRACT 



In 1986 the Bureau of Mines conducted a probability sample survey, Mining Industry Popula- 
tion Survey, to measure such employee characteristics as occupation; principal equipment operated; 
work location at the mine; present job, present company, and total mining experience; job-related 
training during the last 2 years; age; sex; race; and education. The population estimates are necessary 
to properly analyze the Mine Safety and Health Administration (MSHA) injury (includes illness 
and fatality data) statistics; that is, to compare and contrast injury rates for various subpopulations 
in order to identify those groups that are exhibiting higher than average injury rates. 

This report uses the survey's results to characterize the U.S. sand and gravel mining workforce 
from March through September 1986. Similar reports have been prepared for the metallic, stone, 
and nonmetallic mining industries, as well as for the entire metal and nonmetal mining (includes 
metallic, stone, sand and gravel, and nonmetallic industries) sector and the coal mining sector. 



'Mathematical statistician (now with Bureau of Labor Statistics, Washington, DC). 

"Statistical assistant. 

Twin Cities Research Center, Bureau of Mines, Minneapolis, MN. 



INTRODUCTION 



According to the occupational safety and health (OSH) statistics 
published annually by the U.S. Department of Labor, Bureau of 
Labor Statistics, the mining industry (excluding oil and gas extrac- 
tion) always has had one of the highest injury incidence rates among 
the major industry divisions. One of the primary objectives of the 
Bureau of Mines is to conduct research in the area of health and 
safety of the nation's miners, aimed at reducing the incidence rate 
of work-related injuries (includes illnesses and fatalities) in the 
domestic mining industry. In order to reduce the overall incidence 
rate, the Bureau needs to identify which groups or subpopulations 
of the workforce are exhibiting higher than average incidence rates. 

To identify the high-risk groups, information about the injured 
workers and about the entire workforce is required. Present regula- 
tions permit MSHA to collect information on all mine injuries 
requiring medical attention. Hence, a data base containing various 
characteristics on the injured workforce is available. Since similar 
information about the entire workforce was not available, the Bureau 
conducted a probability sample survey called the Mining Industry 
Population Survey (MIPS), also known as the demographics survey, 
to collect the necessary data. The 1986 survey measured the follow- 
ing characteristics: job title or occupation, principal equipment 
operated, work location at mine, experience at present job, 
experience at present company, total mining experience, job-related 
training during the last 2 years, age, sex, race, and education. This 
demographics survey provided information about the population at 
risk and will aid research in pinpointing the hazardous segments 
of the population, as illustrated by the following example. 

From MSHA's injury data base, it is known that 1,399 males 
and 1 1 females working in the U.S. sand and gravel mining industry 
were injured in 1986. If information about the population at risk 
(i.e. , the number of male and female workers for the sand and gravel 
mining industry in 1986) is not known, then it is not valid to draw 
the conclusion that male miners are at a much higher injury risk 
than female miners. The estimates from the demographics survey 
show that there were a total of 34,088 male workers and 2,814 
female workers (table E-15) employed in U.S. sand and gravel 
mining in 1986. Of these workers, the nonoffice workforce iden- 



tified by occupation or job title consists of 32,949 males and 790 
females (table E-7) . The reason for excluding office workers from 
the analysis is to account for some of the obvious difference in job 
risk. It should be noted that in the office worker category only 3 
pet are males and 72 pet are females (table E-15). The added in- 
formation on the population puts the injury statistics in a better 
perspective, as shown in table 1. 



Table 1.— Population and injury statistics for 1986 sand and 
gravel mining sector 





Population 
statistics 




Injury 


statistics 






Workers 


pet 


Injuries 


pet 


Lost 
workdays 


pet 


Male .... 
Female . . 


32,949 
790 


97.7 
2.3 


1,399 
11 


99.2 
.8 


20,594 
151 


99.3 

.7 


Total . . . 


33,739 


100.0 


1,410 


100.0 


20,745 


100.0 



Since the difference between the distribution of workers and 
injuries, as well as lost workdays, is relatively large, it would be 
interesting to further investigate the source of variation. Could the 
source be job mix by sex? 

Hence, the present research will aid in finding solutions to 
reduce the injury incidence rates for the high-risk groups. That is, 
the collected information will be used to compare and contrast the 
demographics composition of the hazardous groups with those of 
the safer groups. Thus, through present research, the differences 
and similarities between the two groups can be defined. 

The purpose of this report is to provide the U.S. sand and gravel 
mining population estimates for March through September 1986 
by various characteristics. This information is essential to perform- 
ing the injury data analysis that is the ultimate goal of the survey. 

In addition to this report, there are three companion reports 
(/-5) 3 covering the metallic, stone, and nonmetallic mining 
industries. Summary reports have been published for the entire metal 
and nonmetal mining industry (4) and the coal mining industry (5). 



ACKNOWLEDGMENTS 



The authors thank the officials of the U.S. Department of Labor, 
MSHA, for submitting the MIPS justification package to the Office 
of Management and Budget for its clearance to collect the data. 
Special thanks go to Kathy Snyder, public affairs specialist. Office 



of Information and Public Affairs. MSHA. for initiating the study, 
and to Edwin Thomasson. research liaison officer. Technical 
Support. MSHA. for his continuous effort and support. 



SURVEY METHODOLOGY 



POPULATION 

The MIPS covered all workers employed in the anthracite coal 
(SIC 4 111), bituminous coal (SIC 121), metal (SIC 101-106, 109, 
281), stone (SIC 141, 142, 324, 327), sand and gravel (SIC 144). 
and nonmetal (SIC 131, 145, 147, 149, 289, 299) mining industries 
of the United States during the period March through September 
1986. This report gives estimates only for the sand and gravel mining 
sector. 

The information pertaining to the mine employees included in 
the survey was collected through the mine operators, because a com- 
prehensive sampling frame (name and address file) of the workers 



in mine establishments was not available, and cost considerations 
prohibited the data collection through personal visits. The number 
of universe units (establishments under MSHA's jurisdiction) 
covered by the scope of this survey was approximately IS. 350. with 
a total employment level of about 350.000. The number of 
establishments and employment for the sand and gravel mining was 
about 5.580 and 40.000. respectively. The scope of the data for 



'Italic numbers in parentheses refer to items in the list of references preceding the 
appendixes at the end of this report. 

4 The Standard Industrial Classification tSIC) was revised in 1987; the industn group 
numbers used here are those in effect at the time of the MIPS 



the employees covered by this survey is the same as that of the data 
collected by MSHA form 7000-1 for mine accidents, injuries, 
illnesses, and fatalities, and MSHA form 7000-2 for quarterly mine 
employment. The collection of the fundamental statistics reported 
on these two forms is required by law (30 U.S.C. 813; 30 CFR 50). 



SAMPLE 

The principal feature of the survey sample design was its use 
of two-stage stratified random sampling. The primary sampling units 
(first stage) were the mine establishments; the secondary sampling 
units were employees within each of the chosen mine establishments. 
The characteristics used to stratify the primary units were the in- 
dustry (anthracite coal, bituminous coal, metal, stone, sand and 
gravel, nonmetal); mine type (underground, surface, plant or mill); 
employment size class (1-19, 20-49, 50-99, 100-249, 250-499, 
500-999, 1,000 and above); and status code (active, intermittent). 
Since the first three stratification characteristics are highly correlated 
with the characteristics that the survey was to measure, use of 
stratified sampling increased the efficiency of the sample design 
and thus resulted in a smaller required sample size. The fourth 
characteristic, status code, was chosen so that nonresponse adjust- 
ment could be made within more homogenous groups. This is 
desirable because proportionately higher numbers of nonmailable, 
out-of-business, refusal, etc., responses are reported from inter- 
mittent mine establishments than from active mine establishments. 

The sampling frame used for this survey was the 1985 
preliminary address and employment file maintained by MSHA. 
A probability sample of 863 sand and gravel mining establishments 
from a universe of 5,579 sand and gravel mining establishments 
was selected by stratifying the frame as previously described and 
using a systematic sampling procedure with a random start for each 
stratum. The employees within an establishment were selected by 
using a systematic sampling procedure with a common random start 
for each employment size class. 

A brief description of the sample allocation is as follows. For 
larger employment size classes, the allocation procedure placed all 
of the establishments on the frame in the sample as primary sampling 
units from which the employees were subsampled at a low frequency 
rate. As employment size class decreased, smaller and smaller 
proportions of the establishments were included as primary sampling 
units, but the employees within the establishments were subsampled 
at a higher frequency rate. The use of this procedure gave each 
employee, to the extent possible, about the same probability of 
inclusion in the sample, thus reducing the sampling variability. In 
order to limit the response burden for any one establishment, a 
maximum sample of 50 employees per establishment was selected. 



DATA COLLECTION 

The MIPS was conducted from March through September 1986 
by mail questionnaire through the Bureau's Twin Cities (MN) 
Research Center. A reproduction of the original letter, followup 
letter, and the questionnaire bearing the Office of Management and 
Budget clearance number authorizing collection of the data are 
included in appendix F. 

The response status for the sand and gravel mining sector from 
the original and followup mailings, as well as from telephone calls 
to the nonrespondents, is summarized here. From a total popula- 
tion of 5,579 sand and gravel mining establishments, the survey 
sampled 863 operations. The overall response and rate were 810 
and 94 pet, respectively. There were 129 out-of-scope returns (i.e., 
out of businesses, nonmailables, duplicates, temporary inactives, 
and new businesses under construction); the remaining 734 returns 



were within the scope of the survey (i.e., nonrespondents, usables, 
refusals, and unusables). Of the 734 in-scope records, 646 were 
usables. Thus, the survey achieved a usable response rate of 88 pet. 
A brief description of the response terms follows: 



Response code 



Description 



Nonrespondent Received no response from the 

establishment. 
Usable Establishment provided usable 

data. 
Refusal . Establishment refused to provide 

any data. 
Unusable Establishment provided data that 

were not in usable format. 
Nonmailable Establishment's address was 

either insufficient or wrong. 
Duplicate Data were combined with another 

establishment's data. 
Out-of-business Establishment was permanently 

closed. 
New business Establishment was in development 

stage. 
Temporary inactive .... Establishment was temporarily 

not operating. 

As part of the data collection phase, all the returns were 
reviewed and edited for completeness and reasonableness of the 
data. Whenever there were inconsistencies, the respondents were 
called for reconciliation. Also, almost all of the respondents that 
had initially refused to participate in the survey were contacted by 
phone. Approximately 80 pet of these respondents ultimately sup- 
plied data. Adjustments for those mine establishments that did not 
supply the data, or supplied partial data, are explained in the 
"Estimation Procedures" section and in appendix C. 



DATA CODING, ENTERING, AND EDITING 

The returns underwent a very comprehensive review and editing 
process in order to (1) minimize the reporting differences among 
the respondents (establishments), (2) ensure consistency of coding 
among the individual worker entries, (3) ensure the accuracy of 
the data entry, and (4) ensure compatibility of occupation and equip- 
ment coding with the MSHA injury data base. 



ESTIMATION PROCEDURES 

In a simple random sampling plan, all units are sampled with 
the same sampling ratio. To derive the population estimates, the 
sample units are weighted (replicated) by the inverse of the sampling 
ratio. Because of efficiency consideration, the data for this 
demographics study were collected using a complex survey design. 
Hence, the data for each worker, the ultimate sampling unit, were 
not equally weighted. Instead, the population estimates were derived 
by weighting data for each worker with the appropriate final weight 
which of the data, was the product of the following three factors: 
(1) the inverse of the sampling ratio with which the primary sampling 
unit (establishment) was sampled; (2) a nonresponse adjustment 
factor that was computed separately for each sampling stratum and 
assigned to all responding establishments in a stratum. to account 
for those establishments in that stratum that did not respond; and 
(3) the inverse of the sampling ratio with which the secondary 
sampling units (workers) were selected. A detailed discussion of 
the different weights and estimation formulas are given in 



appendix C. In statistical terms, the survey's estimates of the popula- 
tion total were based on a Horvitz-Thompson estimator (6). 

No adjustment was made for partial nonresponse. That is, the 
characteristics that were left blank by the respondents were coded 
as unspecified and were, naturally, weighted by their appropriate 
final weight in computing the population estimates. The percentage 
unspecified for a particular characteristic gives the user an indica- 
tion of the completeness of the schedules. 



GROUPING OF CHARACTERISTICS 

The original data base has detailed data for the characteristics 
mentioned below. For purposes of publication, the detailed data 
were combined into groups. Please contact the authors to obtain 
detailed data or a different grouping of the data for any or all of 
the characteristics. 



Job Title and Principal Equipment Operated 

Since the original data base has about 100 codes for each of 
these two categories (see appendixes A and B), the entries were 
combined into 20 to 25 groups. Similarities of the job title or prin- 
cipal equipment operated and number of workers in each entry were 
two of the main criteria used in forming the groups. 



Employment Size Class 

The classes used for this characteristic are the standard size 
class definition used by MSHA. Because there were very few mines 
for the size class having 100 through 249 employees, the estimates 
for this class were computed separately and then were combined 
with the estimates for employment size class 50 through 99 in order 
to protect the confidentiality of the mines as well as the workers. 
The combined size class is labeled as 50 through 249. 



Present Job, Present Company, and 
Total Mining Experience 

The data for all three of these characteristics were coded only 
as the number of years. It was felt that data were not reliable enough 
to be accurate to the month. The groupings were formed to be as 
compatible as possible to the groupings used by MSHA for its injury 
statistics. 



Job-Related Training During Last 2 Years 

The grouping for this characteristic was formed to reflect the 
definite and logical intervals that various mine operators employ 
and that meets the need of the mine safety personnel. The most 
frequently reported number was 16 h for training during the last 
2 years; this is because MSHA requires a minimum training of 
8 h/yr. Also, MSHA and safety personnel are interested in know- 
ing the percent of workers who receive no training. Hence, both 
and 16 h were categorized separately. 



Age 

The groupings for age were formed to be about the same as 
what MSHA uses for its injury statistics. 



RELIABILITY OF ESTIMATES 

As stated in reference 7: 

All estimates derived from a sample survey are subject 
to sampling and nonsampling errors. Sampling errors occur 
because observations are made on a sample, not on the entire 
population. Estimates based on the different possible samples 
of the same size and sample design could differ. Nonsampling 
errors in the estimates can be attributed to many sources, 
e.g., inability to obtain information about all cases in the 
sample, mistakes in recording or coding the data, definitional 
difficulties, etc. 

Nonsampling errors occur in a census as well as in a sample 
survey. As mentioned earlier, the completed forms underwent a 
very comprehensive review and edit process. This was primarily 
done to minimize the nonsampling errors. 

In a probability sample, the coefficients of variation (CV's), 
which are a measure of the sampling errors in the estimates, can 
be estimated from the survey data. CV's were calculated for the 
basic characteristics as part of the survey estimation process; these 
CV's as well as the corresponding estimates for number of workers 
are given in tables E-41 through E-48. The CV's for other estimates 
can also be derived if requested. The methodology used to com- 
pute the estimated CV's is given below. 

By definition, the CV of any sample estimate is equal to the 
standard error of the estimate divided by the value of the estimate 
(8). In other words, it is a measure of relative variation. Because 
the survey data will be used by numerous researchers to measure 
different statistics (e.g., totals, means, medians, percentages) by 
various cross-classification categories, it was not feasible to use 
the exact formula for the standard error estimates. Hence, a 
generalized formula that approximated the exact formula and that 
was easy to implement for computing all the standard error estimates 
was developed. It should be noted that since the survey uses a com- 
plex sampling design, the usual variance, standard deviation, and 
standard error estimates computed by the software packages are 
no longer valid because they are based on simple random sample 
design. The reliability measures for this survey were computed by 
employing a random group variance technique. A brief descrip- 
tion of it is given in appendix D and a detailed discussion is given 
in reference 9. 

The purpose of producing a reliability measure for this report 
is to define the confidence interval or range that would include the 
comparable complete coverage value. For example, the total number 
of estimated truck drivers for the 1986 sand and gravel mining in- 
dustry was 8.274 (table E-l and E-42) with a CV of 9.5 pet (table 
E-42). Based on this information, the standard error on the total 
number of truck drivers is 786 (estimate x CV = 8.274 x 0.095) 
and the 95-pct confidence interval is 6.702 to 9.846 (8.274 ± 2 
x 786). This means that with 95 pet confidence, it can be said that 
the interval 6,702 to 9.846 includes the total number of truck drivers 
in the sand and gravel mining industry that would have been obtained 
from a census of the frame. 

In general, the smaller the subpopulation size, the larger the 
variability in the estimates. Additionally, the larger the nonresponse. 
the less reliable the estimate may be. As mentioned earlier, 
nonresponse error is considered a nonsampling error. This error 
occurred more frequendy for estimates of job-related training during 
the last 2 years and total mine experience than for other variables 
because conceptually these variables are harder to report. Moreover, 
it is possible that the training estimates might be somewhat biased 
because many respondents filled in 16 h. the minimum number of 
hours required by MSHA over a 2-year period. 



VALIDATION OF ESTIMATES 

Once the estimates were produced, they were validated for 
accuracy and reasonableness by several mining industry specialists. 
Additionally, the total employment for each industry was compared 
to an independent census conducted by MSHA, the results of which 
are reported in references 10 through 14. The injury experience 
reports tabulate the injury-illness-fatality data reported to MSHA 
on form 7000-1 and employment data reported on form 7000-2. 
While the data base used to compile the statistics for these reports 
contains detailed information for the injured victims, it does not 
contain similar information for the entire workforce. The breakdown 
of total employment is available only by type of ore mined, employ- 
ment size class, and work location. Hence, the MIPS was conducted 
so that MSHA injury data could be analyzed in greater detail. 

The data show that the overall employment figures from the 
two sources differed about 9 pet for the sand and gravel mining 
industry, with the MSHA figures being higher than those of the 
demographic survey. The difference in the estimates is caused in 
part by differences in reporting, coverage period, definitions, and 
methodology as explained below for data comparison by employ- 
ment size class and by work location. 

When comparing distribution of workers by employment size 
class, the differences between the data of the total row of table E-l 
of this report and MSHA data as stated in table 3 of reference 12 
are substantial. This is mainly due to the differences in definition 
and methodology. The MIPS classification is based on total employ- 
ment of an establishment as it existed when the respondents filled 
out the questionnaire. MSHA collects employment on a quarterly 
basis, and for each quarter it is possible for the employment to be 
broken into a maximum of four different work locations; hence, 
each establishment may have up to 16 different employment figures. 

Per MSHA's methodology, the size groups are classified 
according to the lowest numbered (primary) subunit's average 



employment of four quarters and not on the total employment of 
an establishment, as is the case with the MIPS. For example, if 
an establishment's annual average employment is 60, but the 
employment for the primary subunit, say underground, is 15, then 
the establishment per MSHA's methodology is classified in size 
class 1 through 19, whereas according to the MIPS procedure it 
is in size class 50 through 99. It should be noted that MSHA 
classification overestimates the employment in smaller size classes. 

In view of the above, the injury data as published in reference 
12 by size class should not be analyzed against the MIPS employ- 
ment size class data. Instead, the analyst needs to retabulate the 
MSHA injury data from the original data tapes so that the size class 
definition corresponds to the MIPS. 

Also, a large difference existed between MIPS and MSHA 
figures for employment distribution by work location. This is 
primarily due to differences in reporting. The employment reported 
to MSHA every quarter is in aggregate numbers for each work loca- 
tion (maximum of four). Generally, this type of reporting results 
in gross approximations in the breakdown of variables such as 
employment. For the MIPS data, the work location was reported 
for each worker in the sample, in the same manner as it is reported 
to MSHA on form 7000-1 for each injured worker. It should be 
noted that the data on work location for individual workers is known 
with more specificity than for the whole population. Hence, it is 
appropriate to analyze the survey work location data with MSHA 
injury statistics. 

Additionally, a small portion of the difference in the two 
estimates is due to the job title category of office workers. The MIPS 
underestimated the number of employees in this category because 
many respondents assumed that these workers very seldom incur 
injuries and therefore were not to be reported. For the purposes 
of injury analysis, the office workers are to be excluded because 
of some of the obvious difference in the injury risk. Hence, the 
difference in counts of office workers does not make any difference. 



SUMMARY OF MAJOR FINDINGS 



The findings of the survey by various cross-classifications are 
given as estimates in tables E-l through E-40 appendix E); tables 
E-41 through E-48 give reliability estimates for the basic 
characteristics and a detailed discussion of their use is given in the 
"Reliability of Estimates" section. If desired, the estimates by some 
other classification criteria including more detailed estimates (e.g., 
distribution of workers by age and experience at present company 
working at the plant or mill location) can be derived from the original 
data base. The following findings are based on the data for the entire 
1986 sand and gravel mining workforce. 

• The total estimated workforce for 1986 was approximately 
37,100 (table E-l). The data in table E-l also indicate that 
68 pet of the workforce was employed in establishments with 
19 or less employees, 25 pet in establishments with 20-49 
employees, and 7 pet in establishments with 50-249 
employees. This indicates that the bulk of the employment 
was in establishments having 19 employees or less. 

• Truck driver was the largest category of workers with 22 
pet employment, followed by front-end loader-forklift 
operator with 16 pet, and plant operator-warehouseman with 
1 1 pet (table E-l). Each of the remaining occupation group- 
ings had fewer than 10 pet of the employees. 

• The distribution of workers by work location was surface 
mine, 72 pet; plant or mill, 16 pet; and office 12 pet (table 
E-3). 



• The job title category manager-foreman-supervisor had the 
highest median experience at job (table E-10), at company 
(table E-l 1), as well as at mining (table E-l 2). It should be 
noted that in this context three types (general, maintenance, 
and working) of manager-foreman-supervisor were combined 
because maintenance and working foreman categories were 
too small. 

• Mean hours of training during the last 2 years was lowest 
(26 h) for the truck driver category (table E-l 3). 

• Of the female employees, 72 pet had the job title category 
office worker, compared with 3 pet of the males (table E-15). 

The following findings are based on sand and gravel mining 
data that exclude the job title category of office worker. 

• The largest category of equipment operated was haulage truck 
with 25 pet of the employment, followed by front-end loader- 
forklift with 20 pet, plant equipment with 15 pet, and none 
with 10 pet (table E-2). 

• The median experience at present job, present company, and 
total mining were 4, 5, and 8 years, respectively (table E-4). 

• Job-related training during the last 2 years was unspecified 
for 35 pet of the workers (table E-5). Of the specified popula- 
tion, mean hours of training were 38, 27, and 39 for size 
classes 1-19, 20-49, and 50-249, respectively, and 35 h for 
all three size classes combined. 



Mean age was about 39 years across all size classes (table 
E-6). The age group 50 and over had the largest number 
of workers (7,821), followed closely by the 40-49 age group 
(6,583). Combined, these two groups made up about 42 pet 
of the workforce. 

Males made up 98 pet of the workforce (table E-7) . Note 
that the 98-pct figure excludes the unspecified category. 
Whites, blacks, and Hispanics made up 84, 5, and 7 pet, 
respectively, of the workforce (table E-7). The remaining 
3 pet workers belonged either to another race or were 
unspecified. 

Of those workers whose education was specified, 70 pet 
had a high school or better education (table E-7). Note that 
this figure is obtained by ( 1 ) summing the workers in the 
categories high school diploma, vocational diploma, some 
college, and college degree, and (2) dividing this sum by 
the total number of workers minus the workers in the 
unspecified category. In this case, it is 21,054 divided by 
29,897. 

The distribution of workers by principal equipment operated 
also varied considerably between males and females (table 
E-21); this was especially true for the categories front-end 
loader-forklift, plant equipment, scale-lab equipment- 
controls, haulage truck, and none. For example, 26 pet of 
the males operated haulage trucks, compared with only 8 
pet of the women. 



82 pet 



70 pet 



76 P=t 75 pet 



78 pet 



66 pet 



58 pet 



15-23 24-26 27-29 30-34 35-39 

AGE, yr 



40-49 



50 + 



Figure 1. — Percentage of 1986 sand and gravel mining 
workforce with at least a high school diploma, by age (excluding 
job title category of office worker, as well as workers whose 
education was unspecified. 



There was a higher percentage of employees with at least 
a high school education under the age of 40 than there were 
of age 40 and over (table E-38 and figure 1); proportion- 
ately more females had a high school or higher education 
than males (table E-39 and figure 2); education by race (table 
E-40) is shown in figure 3. 





87 pet 


70 pet 











MALE 



FEMALE 



Figure 2. — Percentage of 1986 sand and gravel mining 
workforce with at least a high school diploma, by sex (excluding 
job title category of office worker, as well as workers whose 
education was unspecified. 



74 pet 








45 pet 










40 pet 







WHITE 



s_a:n 



HISPANIC 



Figure 3.— Percentage of 1986 sand and gravel mining 
workforce with at least a high school diploma, by race (excluding 
job title category of office worker, as well as workers whose 
education was unspecified. 



APPLICATION OF DATA FOR INJURY ANALYSES 



The ultimate objective of this study is to provide a basis for— 

1. Analyzing the 1986 MSHA sand and gravel mining injury 
statistics and identifying those subpopulations exhibiting higher or 
lower than average injury rates. 

2. Producing some selected estimates by geographic location 
such as regions (east, central, west), MSHA districts, or States, 
and performing injury data analyses. 



3 . Developing an easy to use computerized data base that would 
be available to the researchers to do their own analyses especially 
in the area of targeting injury prevention and training efforts. 

The results from these analyses, which encompass all facets 
of mining operations, can help identify areas where research efforts 
should be devoted to achieve the greatest safety improvements, thus 
preventing creation of unnecessary regulations or crash research 
programs that tend to waste funds. 



RECOMMENDATIONS FOR FUTURE WORK 



1 . After the injury analyses are performed, and the hazardous 
areas or subpopulations have been identified, it would be desirable 
to further investigate their problems and needs. This can be 
accomplished by conducting some special surveys such as an equip- 
ment use survey, maintenance related work survey, small mines 
survey, etc. 

2. Repeat the MIPS and perform the injury analyses period- 
ically, say every 3 to 5 years, in order to study the changing mining 



environment and its impact on mining safety and productivity. When 
the survey is repeated, it is recommended that modifications be made 
to the questionnaire to reflect new needs. It is also recommended 
that the collection of total mine experience and job-related training 
data be eliminated, since these variables are conceptually very hard 
to measure. Also, the variables experience on the job and experience 
with the company should be measured in years only. 



REFERENCES 



1. Butani, S. J., and A. M. Bartholomew. Characterization of the 1986 
Metallic Mining Workforce. BuMines IC 9201, 1988, in press. 

2. . Characterization of the 1986 Stone Mining Workforce. 

BuMines IC 9202, 1988, 43 pp. 

3. . Characterization of the 1986 Nonmetallic Mining Workforce. 

BuMines IC 9204, 1988, 43 pp. 

4. . Characterization of the 1986 Metal and Nonmetal Mining 

Workforce. BuMines IC 9193, 1988, 60 pp. 

5. . Characterization of the 1986 Coal Mining Workforce. 

BuMines IC 9192, 1988, 67 pp. 

6. Cochran, W. G. Sampling Techniques. Wiley, 3d ed., 1977, 429 pp. 

7. U.S. Bureau of Labor Statistics. Occupational Illnesses in the United 
States by Industry, 1985. May 1987, 81 pp. 

8. Hansen, M. H., W. N. Hurwitz, and W. G. Madow. Sample Survey 
Methods and Theory. Wiley, v. 1, 1953, 638 pp. 



9. Wolter, K. M. Introduction to Variance Estimation. Springer- Verlag, 
1985, 440 pp. 

10. U.S. Mine Safety and Health Administration. Injury Experience in 
Metallic Mining, 1986. Inf. Rep. 1158, 1987, 276 pp. 

11. . Injury Experience in Stone Mining, 1986. Inf. Rep. 1160, 

1987, 450 pp. 

12. . Injury Experience in Sand and Gravel Mining, 1986. Inf. 

Rep. 1161, 1987, 111 pp. 

13. . Injury Experience in Nonmetallic Mining, 1986. Inf. Rep. 

1159, 1987, 291 pp. 

14. . Injury Experience in Coal Mining, 1986. Inf. Rep. 1157, 

1987, 390 pp. 



APPENDIX A.— SAND AND GRAVEL MINING INDUSTRY JOB TITLE GROUPING 

Description Job title code 

Backhoe-crane-dragline-shovel operator 367, 378, 778, 387 

Beltman-belt repairman 601, 1012, 996 

Blaster 807 

Deckhand-barge and dredge operator 372 

Dozer-heavy and mobile equipment operator 368, 768, 985 

Driller-rock bolter 33, 34, 333, 334, 1056, 46 

Electrician-lampman 402, 602, 603, 385 

Front-end loader-forklift operator 382, 782, 825, 389 

Grader-scraper operator 375, 775, 957 

Laborer-miner-utility man 616, 53, 316, 36, 38, 39, 45, 57, 58, 59, 158, 216, 224, 327, 

386, 395, 609, 624, 663, 710, 716, 874, 997, 1013, 1055 
Manager-foreman-supervisor: 

General 430, 449, 481, 489, 494 

Maintenance 418 

Working 749 

Mechanic-welder-oiler-machinist 404, 604, 605, 1019, 1018, 1060, 394, 608 

Mine technical support 320, 393, 396, 414, 423, 456, 464, 495, 593, 594, 920, 921, 

930, 965, 998, 1014 

Office worker 497 

Plant operator-warehouseman 374, 379, 380. 388, 390, 392, 1022 

Shuttle car-tram operator 850, 28, 29, 269, 373, 728, 962, 969 

Truck driver 376, 776 



Code Description 

28 Scoop tram operator 

29 Mucking machine operator 

33 Driller helper, underground 

34 Exploration driller, underground 

Longhole driller, underground 

Prospect driller, underground 

Diamond driller, underground 

36 Continuous miner operator 

38 Cutting machine operator 

39 Hand loader 

Trammer 
45 Hangup man 

Rockman 

Raise blaster 

Chute blaster 

Rock handler 
46 Pinner 

Truss bolter 

Rock bolter 

Roof trimmer 

Roof man 

Scaler operator 

Roof bolter 
53 Nipper 

Utility man 

57 Stope miner 

58 DXC miner 

Drift miner 

59 Raise miner 

158 Rock machine operator, underground 

216 Trackman 

224 Trainees, underground 



Code Description 

269 Chute puller, underground 

Locomotive operator 

Car loader underground 

Whistle punk, underground 
316 Service truck operator 

Laborer 

Track gang, surface 

Surface worker 

Utility man, surface 

Pumper, surface 

Tamping machine operator 
320 Cage attendant, surface 

Aerial tram — outside only 

327 Surface miner 

333 Driller helper 

334 Carriage-mounted drill operator, surface 

Wagon drill operator, surface 

Churn driller, surface 

Rotary drill operator 

JP drill operator, surface 

Air-track driller, outside only 
367 Backhoe operator 

Power shovel operator 

Pitman 
368 Dozer operator 

Track operator helper, surface 

Tractor operator, surface 
372 Deckhand 

Dredge operator 

Barge attendant 

Barge loader 

Boat operator 



Code Description 

373 Car dropper 

374 Storekeeper 

Blunger 

Process operator 

Sandbox operator 

Mill operator 

Reagent operator 

Car loader, surface 

Warehouseman 

Shipping 

Media operator 

Breakerman 

Crusher operator 

Sewing machine operator 

Boney preparation plant operator 

Packaging 

Cleaning plant operator 

Truck loader 

Bagger-baler 

Preparation plant operator 

Cobber 

375 Grader operator, surface 

376 Truck driver, surface 

378 Dragline operator 

Dropball operator 

Crane operator, surface 
379 Kiln operator 

Calciner 

Dryer operator 

380 Fine coal plant operator 

382 Loader operator 

Front-end loader operator, surface 

Pan operator 

Scraper operator 

Highlift operator 

Payloader operator 

385 Lampman 

386 Refuse truck driver 

387 Rotary bucket excavator operator 

388 Separator operator 

Scalper 

Shaker operator 

Screen operator 

389 Forklift operator 

390 Silo operator 

392 Washery operator 

Topman 

Skip dumper 

Binman 

Scrubber operator 

Tipple operator-attendant 
393 Scaleperson 

Weighman-weighmaster 

394 Carpenter 

395 Water truck operator 

396 Watchman 

Security guard 
398 Sawyer 

Stone finishing 

399 Dimension stone cutter-polisher 

402 Master electrician 

404 Master mechanic 



Code Description 

414 Laboratory assistant 

Analyst 

Laboratory technician 

Laboratory supervisor 

Quality control 

Dust sampler 

Emission control specialist 
418 Maintenance supervisor 

Maintenance foreman 

423 Surveyor 

430 Assistant mine manager 

Assistant mine foreman-vice president 
449 Mine owner 

Assayers 

President 

General foreman 

Mine manager 

Mine foreman 
456 Engineer 

Metallurgist-geologist 

Chemist 

464 Inspector 

481 Superintendents 

Project managers 

Coordinators 

Supervisors 

489 Outside foreman 

494 Plant manager 

Mill manager 

Plant foreman 

Mill foreman 
495 Safety coordinator 

Safety manager 

Safety director 

Environmental coordinator 

Safety engineer 
497 Office help 

Computer operator 

Controller 

Clerk 

593 Nurse 

594 Training specialist 

601 Conveyor man 

Belt walker 

Belt installer 

Tunnel worker 

Tailpiece man 

Belt mover 

Mobile bridge carrierman 

Beltman 
602 Lineman 

Electrician 

603 Electrician helper 

604 Fueler 

Boilermaker 

Plumber 

Pipefitter 

Boiler operator 

Pipe man 

Boiler trainee 

Mechanic 

Repairman 

Mill wright 



10 



Code 



Description 



Code 



Description 



605 Mechanic helper 

608 Mason 

609 Supplyman 

Material man 
616 Rock picker 

Parts runner 

Groundman 

Unit helper 

Bathhouse attendant 

Pointman 

Laborer 

Slate picker 

Roustabout 

Extra man 
624 Trainees 

Apprentice 
663 Ledgeman 

Quarry man 

Miner, not elsewhere classified 

Shaft miner 

Probeman 
710 Propman 

Timberman 
716 Cement man 

Form man 

Grizzly tender 
728 Gizmo operator 

Load-haul-dump operator, underground 
749 Shift boss 

Foreman-leadman 

Bullgang foreman 

Labor foreman 

Section boss-foreman 

768 Heavy equipment operator 

775 Grader operator, underground 

776 Truck driver, underground 

778 Cherry picker 

Crane operator, underground 

Dragline operator, underground 

Backhoe operator, underground 

Gradall operator 

Front-end loader operator, underground 
807 Chargeman 

Shot firer 

Powder man 

Blaster 

Airdox operator 

Loading hole shooter 

Powder monkey 



825 Bobcat operator 

850 Ramcar operator 

Shuttle car operator 

Buggy operator 

874 Mine equipment operator 

920 Cager 

921 Hoist operator 

Hoist engineer 

Shaftman 

930 Skip tender 

957 Scraper operator 

962 Car runner, surface 

Trip rider 

Brakeman 

Flagman 

Car rider 

Conductor 

965 Dispatcher 

969 Swamper 

Motorman 

Switchman 
985 Heavy equipment operator, surface 

Mobile equipment operator, surface 

996 Feeder man 

997 General or many equipment operator 

998 Janitor 

Bag stenciler 

Prospector 

Painter 

1012. . . .Belt repairman 

Belt vulcanizer 

1013. . . Cleanup man 

1014. . . .Sampler 
1018. . . .Lube man 

Greaser-oiler 
1019... Welder 
1022. . . .Dump man 

Dump operator 
1055. . . .Chainman 

1056 Rock driller 

1060. . . .Machinist 

Shopman 

Shop foreman 

Bit sharpener 



11 



APPENDIX B.— SAND AND GRAVEL MINING INDUSTRY 
EQUIPMENT OPERATED GROUPING 



Description Equipment code 

Backhoe-crane-dragline-shovel 60, 14 

Belt 13, 96 

Dozer-heavy and mobile equipment 8, 85 

Drill (underground)-rock bolter 53, 54, 49 

Drill (surface) 9 

Explosives 47 

Front-end loader-forklift 24, 23 

Grader-scraper 52, 57 

Handtools (powered and nonpowered) 28 

Many equipment 97 

Miscellaneous utility equipment 95, 12, 16 

Plant equipment 40, 7, 10, 11, 15, 18, 22, 26, 32, 39, 46, 51, 58, 69, 82„83 

Pump 48 

Scale-lab equipment-controls 92, 80, 91 

Shuttle car-locomotive 61, 34, 33, 41, 42, 43, 65 

Truck (haulage) 44, 45 

Truck (utility)-personnel carrier 67, 37, 66 

Welding machine-lathe 70, 5 

None 

Not elsewhere classified 98, 68, 71, 81, 88 

Unspecified 99 



Code Description 

None 

5 Drill press 

Bench grinder 

Lathe 
7 Boats 

Barges 

Water transportation 
8 Bulldozer 

Dozer 

Crawler tractor 
9 Carriage mounted drill 

Jumbo drill 

Churn drill 

Rotary drill 

Jet piercing drill 

Airtrack compressor drill 
10 Chute 

Airslide 
11 Classifier 

Cyclones 
12 Continuous miner 

Dosco miner 
13 Belt feeder 

Mobile bridge carrier 

Conveyor 

All types belts 



Code Description 

14 Cherry picker 

Basket scaler 

Scaling machine 

Rock or dropball 

Boom hoist 

Derrick 

Crane 

Gantry 
15 Breaker 

Crusher 
16 Cutting machines 

Undercutter 

Chain cutter 

18 Dredge 

22 Precipitator heavy media bath 

Filters 

Flotation machines 

23 Forklift 

24 Highlift 

Skip tender 

Front-end loader 

Payloader 

26 Grizzlies 

28 Handtools (powered and nonpowered) 

Ram jack 
32 Impactor 



12 



Code Description 

33 Scoop tram 

Unitrac 

Load-haul-dump 

Teletram car 

Bobcat, underground 
34 Locomotive 

Trammer 

Tow-motor 

Lorry car 

Rail-mounted locomotive 
37 Porta bus 

Mancar 

Golf cart 

Mantrip 

Rail runner 

Rail rover 

Personnel carrier 

Boss buggy 

Jeep 
39 Grinding mills 

Ball or rod mills 
40 Milling machinery 

Block press 

General plant equipment 
41 Nipper truck, underground 

Mine car, underground 

Underground flatcar 

Timber truck, underground 
42 Mine car, surface 

Ore-coal car, surface 

Boxcar, surface 

Hopper car, surface 
43 Mucking machine 

Overshot loader 

44 Ore haulage trucks, offhighway 

45 Payloader ore haulage, onhighway 

46 Bagger 

Sewing machine 

Packaging machine 
47 Pneumatic blast agent loader 

Pop shooter 

Driller loader 

Prill loader 

Powder buggy 

Explosives 

48 Pump 

49 Raise borer 

51 Raw coal storage 

Tipple 

Dump bins 
52 Roadgrader 

Motor grader 

Motor patrol 
53 Jackleg 

Drifter drill 

Airleg 

Diamond drill 

Track drill 

Jumbo drill 

Rock drill 

Buzzy drill 

Jackhammer 

Hydraulic drill 

Stoper drill 



Code Description 

54 Pinner 

Roof bolting mach 
57 Pan scraper 

Scoop, surface 

Self-loading scraper 

Tractor scraper 

Scraper loader 
58 Shaker 

Vibrator 

Screen 
60 Dragline 

Dragline bucket 

Backhoe 

Power shovel 

Clamshell 
61 Buggy 

Shuttle car 

Ram car 
65 Track maintenance 

Track repair equipment 
66 Tractor, underground 

Elkhorn 

Supply car 
67 Trash truck 

Service truck 

Utility truck 

Water truck 

Dump truck 

Pickup truck 
68 Tugger 

Air winch 

69 Washers 

70 Welding machine 

Torch 
71 Machines, not elsewhere classified 

Rock rake 

Drilling rigs 

Impact roller 

80 Lab equipment 

81 Rigs, not elsewhere classified 

82 Boilers 

83 Furnaces 

Calciners 

Kilns 

Dryers 
85 Heavy equipment 

Mobile equipment 

88 Diesels 

91 Controls 

Consoles 

92 Scales 

95 Miscellaneous utility equipment 

96 Feeders 

97 Many-all types of equipment 

98 Not elsewhere classified 

99 Not specified 



13 



APPENDIX C— ESTIMATION PROCEDURES 



Establishment weight. —Suppose one out of every five mine 
establishments in a sampling stratum (industry-mine type-employ- 
ment size class-status) was selected. Then, the sampling ratio is 
1-5, and the establishment weight (EWT) is 5.00, the inverse of 
the sampling ratio. 

Nonresponse adjustment factor. —Also suppose in a given 
sampling stratum, 80 pet of the establishments that were within the 
scope of the survey responded. Then, the nonresponse adjustment 
factor (NRAF) is 1.25 (i.e., 100/80). 

Worker weight. — Additionally, there was the sampling ratio 
with which the workers in the establishment were sampled; the 
worker weight (WWT) ranged from 1.00 to 30.00 (see the first 
page of the MIPS questionnaire in appendix F). Theoretically, all 
the workers in a sampling stratum should have had the same weight. 
Hence, there would have been no need to assign weight at the worker 
level, as the worker weight could have been incorporated into the 
establishment weight. In practice, however, this is seldom the case 
because for a few establishments the employment level changes from 
what it was on the sampling frame to the time of the survey data 
collection. Since all the establishments did not report in the same 
employment size class that they were sampled in, it was necessary 
to also assign each worker a weight. 

Final weight. — For the purpose of computing the estimates, 
each worker was assigned a final weight (FWT) which was the 
product of establishment weight (EWT), nonresponse adjustment 
factor (NRAF), and the worker weight (WWT). That is, FWT = 
EWT X NRAF X WWT. 

Estimates of number of workers.— The estimates of the total 
number of workers were computed by (1) summing the final weights 
over the appropriate domain, and (2) rounding the sum to the nearest 
integer. 

Example: To estimate the total number of truck drivers: 

1. Compute x = S FWTj. 

ieD 
Where the domain, D, was the set of all records 
(workers) that had an occupation code of truck 
driver. 

2. Compute y = round (x). 



Estimates of mean. —The estimates of mean age (training) were 
computed by summing over the appropriate domain (1) the product 
of age (training) and final weight, (2) the final weights, and then 
(3) dividing the sum of the products by the sum of the weights and 
rounding the result to the nearest whole number. It should be noted 
that for each domain only those entries where age (training) was 
specified were included in the computation. 

Example: To estimate the mean age of the truck drivers: 



1. Compute x 



2. Compute y 



I (Age ; * FWTj). 
i£D 

I FWT,. 
ieD 



Where domain, D, is the set of all records that 

had an occupation code of truck driver with age 

being specified. 

3. Compute z = round (x/y). 
Estimates of median.— The estimates of median job, company, 
and mining experience were derived by (1) sorting over the domain 
the records in ascending order of the experience for which the 
median statistic was desired, (2) computing the total number of 
workers (NW) in the domain by summing the final weights, and 
(3) selecting the experience corresponding to the middle worker(s) 
in the ordering. That is, if NW is an odd number, then the median 
experience is the experience corresponding to the (NW/2 + l)th 
worker in the ordering; if NW is an even number, then the median 
experience is the midpoint (rounded to the nearest integer) of the 
experience corresponding to the (NW/2)th and (NW/2 + l)th 
worker in the ordering. As with the mean estimates, the median 
estimates also excluded those entries in the domain with unspecified 
experience. 



14 



APPENDIX D.— RELIABILITY OF ESTIMATES: RANDOM GROUP VARIANCE TECHNIQUE 



The random group method of variance estimation employed 
in this study consisted of selecting eight samples using the same 
sampling scheme for each sample as the parent sample. The primary 
sampling units (establishments) were divided into two sets. The first 
set consisted of noncertainty (probability of selection less than 1 .00) 
primary sampling units sorted by their original industry-mine type- 
employment size class-status. A random integer, say j, between 1 
and 8 was generated. The first primary unit in the ordering was 
assigned to the random group j, the second to the random group 
j + 1, and so forth in a modulo 8 fashion. Then, the secondary 
sampling units (workers) were assigned the same random group 
number as the primary unit to which they belonged. The second 
set consisted of all secondary sampling units belonging to the cer- 
tainty (probability of selection equal to 1 .00) primary sampling units. 
The secondary sampling units were sorted by the same scheme as 
above, and a random integer, say k, between 1 and 8 was generated. 
Then, the first secondary unit in the ordering was assigned to the 
random group k, the second to the random group k + 1, and so 
forth in a modulo 8 fashion. Hence, each worker belonged to a 
random group. For a more detailed discussion of the random group 
technique, the reader is referred to reference 9 of the main text. 

The following procedure was followed in computing the 
estimated variance (var), standard error (s), and the coefficient of 
variation (CV) for the estimated number of workers belonging to 
a particular category. 



1. The domain (i.e., category) was defined. 

2. A separate estimate for total number of workers, 9 { , for 
each of the eight random groups was computed. If any random 
group was empty, then a zero was assigned to that random 
group. 

3. Total number of workers, 0, for all eight groups was 
computed as 

= 0, + 2 + . . . + 8 . 

4. The mean number of workers per group was computed as 

_A A 

= 0/8. 

A 

5. The variance for was computed as 

8 A 
var (0) = 8 I (0, - 0) 2 . 
i = l 7 

6. The standard error of was computed as 

s(0) = v' var (0). 

7. The CV for was computed as 

CV(0) = s(0) x 100.0. 




15 



APPENDIX E.— SAND AND GRAVEL MINING 1986 WORKFORCE ESTIMATES 

Table E-1.— Sand and gravel mining 1986 workforce estimates: job title, by employment size class 1 

V19 20-49 50-249 Total 

9 9 Workers pet Workers pet Workers pet Workers pet 

Backhoe-crane-dragline-shovel operator 932 4 251 3 96 3 1,279 3 

Beltman-belt repairman 58 103 1 47 2 208 1 

Blaster 3 3 

Deckhand-barge and dredge operator 598 2 211 2 44 2 853 2 

Dozer-heavy and mobile equipment operator 1,046 4 214 2 121 4 1,381 4 

Driller-rock bolter 21 24 11 56 

Electrician-lampman 3 27 45 2 75 

Front-end loader-forklift operator 4,867 19 859 9 207 7 5,933 16 

Grader-scraper operator 217 1 121 1 14 1 352 1 

Laborer-miner-utility man 1,818 7 866 9 235 8 2,918 8 

Manager-foreman-supervisor: 

General 2,662 11 695 8 109 4 3,466 9 

Maintenance 11 16 14 40 

Working 155 1 147 2 85 3 387 1 

Mechanic-welder-oiler-machinist 1,495 6 1,234 14 571 21 3,299 9 

Mine technical support 919 4 397 4 123 4 1 ,439 4 

Office worker 2,201 9 740 8 247 9 3,188 9 

Plant operator-warehouseman 2,862 11 721 8 335 1 2 3,91 8 1 1 

Shuttle car-tram operator 11 14 7 32 

Truck driver ' 5,324 21 2,478 27 473 17 8,274 22 

Total 25,200 100 9,117 100 2,783 100 37,100 100 

1 MSHA size groups are based on the annual average employment of the primary subunit and not on the total employment; hence, MSHA published injury 
statistics by size groups should not be analyzed against these data. 
2 As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Table E-2.— Sand and gravel mining 1986 workforce estimates: 1 principal equipment operated, by employment size class 2 

~ ! " ; " Tl9 20-49 50-249 total 

Equipment operated grouping 3 ■ — — ■ — — ; 

Workers pet Workers pet Workers pet Workers pet 

Backhoe-crane-dragline-shovel 969 4 258 3 96 4 1,323 4 

Belt 80 130 2 37 1 247 1 

Dozer-heavy and mobile equipment 808 4 246 3 110 4 1,164 3 

Drill (underground)-rock bolter 3 3 

Drill (surface) 17 24 11 52 

Explosives 3 3 

Front-end loader-forklift 5,496 24 921 11 223 9 6,640 20 

Grader-scraper 254 1 123 1 23 1 400 1 

Handtools (powered and nonpowered) 1,333 6 973 12 481 19 2,787 8 

Many equipment 276 1 51 1 326 1 

Miscellaneous utility equipment 953 4 620 7 160 6 1,733 5 

Plant equipment 3,872 17 859 10 314 12 5,045 15 

Pump 212 1 4 216 1 

Scale-lab equipment-controls 625 3 281 3 79 3 985 3 

Shuttle car-locomotive ' 14 7 21 

Truck (haulage) 5,523 24 2,498 30 479 19 8,501 25 

Truck (utility)-personnel carrier 107 72 1 31 1 211 1 

Welding machine-lathe 308 1 326 4 174 7 808 2 

None 2,118 9 905 11 278 11 3,300 10 

Not elsewhere classified 19 35 3 57 

Unspecified 23 42 25 1 90 

Total 22,999 100 8,377 100 2,536 100 33,912 100 

1 Excluding job title category of office workers. 

2 MSHA size groups are based on the annual average employment of the primary subunit and not on the total employment; hence, MSHA published injury 
statistics by size groups should not be analyzed against these data. 
3 See appendix B for detailed explanation of equipment operated grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Table E-3.— Sand and gravel mining 1986 workforce estimates: work location at mine, by employment size class 1 

... , , " V19 20-49 50-249 total 

Work location 

Workers pet Workers pet Workers pet Workers pet 

Surface mine 18,388 73 6,284 69 1 ,959 70 26,631 72 

Plant or mill 3,728 15 1,797 20 502 18 6,026 16 

Office 3,085 12 1 ,035 1 1 322 12 4,443 12 

Total 25,200 100 9,117 100 2,783 100 37,100 100 

1 MSHA size groups are based on the annual average employment of the primary subunit and not on the total employment; hence, MSHA published injury 
statistics by size groups should not be analyzed against these data. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



16 



Table E-4.— Sand and gravel mining 1986 workforce estimates: 1 experience at job, company, and mining, by employment size class 2 

~ \ VI9 20-49 50-249 Total 

Experience, yr 

Workers pet Workers pet Workers pet Workers pet 

At present job: 

0<to<1 4,598 20 1,504 18 523 21 6,625 20 

1<t0<2 2,741 12 755 9 316 12 3,812 11 

2< to <3 2,387 10 582 7 245 10 3,214 9 

3< to <5 2,985 13 803 10 143 6 3,932 12 

5<tO<10 3,910 17 1,379 16 568 22 5,856 17 

1CKtO«20 3,636 16 917 11 332 13 4,884 14 

20< 1,428 6 527 6 217 9 2,172 6 

Unspecified 1,313 (3 1,911 23 193 8 3,417 10 

Total 22,999 TOO 8,377 100 2,536 TOO 33,912 100 

Median yr . . 4 NAp 5 NAp 5 NAp 4 NAp 

At present company: 

0<tO<1 3,865 17 1,477 18 477 19 5,818 17 

1<to<5 7,800 34 2,320 28 578 23 10,698 32 

5< to <10 4,396 19 1 ,641 20 606 24 6,642 20 

10<tO«15 2,774 12 896 11 264 10 3,934 12 

15<tO«20 1,479 6 711 8 228 9 2,418 7 

20< to <25 680 3 439 5 161 6 1 ,281 4 

25< to <30 486 2 303 4 94 4 883 3 

30< 524 2 347 4 129 5 999 3 

Unspecified 995 4 243 3 1 ,238 4 

Total 22,999 TOO 8,377 TOO 2,536 TOO 33,912 100 

Median yr . . 5 NAp 7 NAp 7 NAp 5 NAp 

Total mining: 

0<tO<1 2,282 10 809 10 348 14 3,439 10 

1<to<5 5,643 25 1,245 15 487 19 7,375 22 

5<to«10 4,139 18 1,165 14 548 22 5,852 17 

10<tO<15 2,902 13 675 8 259 10 3,835 11 

15< to <20 1 ,803 8 455 5 208 8 2,466 7 

20<tO<25 972 4 238 3 150 6 1,361 4 

25<tO«30 643 3 188 2 81 3 912 3 

30< 778 3 246 3 90 4 1,114 3 

Unspecified 3,837 17 3.355 40 367 14 7,558 22 

Total 22,999 TOO 8,377 TOO 2,536 TOO 33,912 TOO 

Median yr. . 8 NAp 8 NAp 7 NAp 8 NAp 

NAp Not applicable. 

1 Excluding job title category of office workers. 

2 MSHA size groups are based on the annual average employment of the primary subunit and not on the total employment; hence, MSHA published injury 
statistics by size groups should not be analyzed against these data. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Table E-5.— Sand and gravel mining 1986 workforce estimates: 1 training received, by employment size class 2 

~T ~ '. ', I ~ VI9 20-49 50-249 Total 

Job training for last 2 yr, h — - — — ■ — 

Workers pet Workers pet Workers pet Workers pet 

4,907 21 1,098 13 127 5 6,132 18 

1-8 1,946 8 387 5 176 7 2.509 7 

9-15 605 3 167 2 130 5 902 3 

16 2,414 10 1,422 17 401 16 4,238 12 

17-40 2,647 12 860 10 252 10 3,759 11 

41-80 1,661 7 569 7 557 22 2.786 8 

81-160 792 3 76 1 79 3 947 3 

161 + 625 3 72 1 36 1 733 2 

Unspecified 7,402 32 3,726 44 778 31 11.905 35 

Total 22,999 100 8,377 100 2.536 100 33.912 100 

Mean job training h . . 38 NAp 27 NAp 39 NAp 35 NAp 

NAp Not applicable. 

Excluding job title category of office workers. 

2 MSHA size groups are based on the annual average employment of the primary subunit and not on the total employment; hence, MSHA published injury 
statistics by size groups should not be analyzed against these data. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



17 



Table E-6— Sand and gravel mining 1986 workforce estimates: 1 age distribution, by employment size class 2 

1 to 19 20 to 49 50 to 249 Total 

9 ' y Workers pet Workers pet Workers pet Workers pet 

15-20 443 2 187 2 91 4 722 2 

21-23 1,247 5 339 4 158 6 1,745 5 

24-26 2,215 10 508 6 157 6 2,881 8 

27-29 2,084 9 612 7 224 9 2,920 9 

30-34 3,099 13 1,067 13 348 14 4,514 13 

35-39 2,962 13 1,014 12 347 14 4,323 13 

40-49 4,465 19 1,597 19 521 21 6,583 19 

50+ 5,322 23 1 ,944 23 554 22 7,821 23 

Unspecified 1,161 5 1,108 13 135 5 2,404 7 

Total 22,999 100 8,377 100 2,536 100 33,912 100 

Mean age yr . . 39 NAp 40 NAp 39 NAp 39 NAp 

NAp Not applicable. 

1 Excluding job title category of office workers. 

2 MSHA size groups are based on the annual average employment of the primary subunit and not on the total employment; hence, MSHA published injury 
statistics by size groups should not be analyzed against these data. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Table E-7.— Sand and gravel mining 1986 workforce estimates: 1 sex, race, and education, by employment size class 2 

1 to 19 20 to 49 50 to 249 Total 

Workers pet Workers pet Workers pet Workers pet 

Sex: 

Male 22,239 97 8,231 98 2,478 98 32,949 97 

Female 600 3 132 2 58 2 790 2 

Unspecified 160 1 14 174 1 

Total 22,999 100 8,377 100 2,536 100 33,912 100 

White 20,242 88 6,622 79 1 ,780 70 28,644 84 

Black 936 4 501 6 305 12 1 ,742 5 

Hispanic 1,253 5 891 11 304 12 2,448 7 

Other 338 1 83 1 35 1 456 1 

Unspecified 230 1 280 3 112 4 622 2 

Total 22,999 100 8,377 100 2,536 100 33,912 100 

Education level: 

Some elementary 1 ,674 7 898 1 1 239 9 2,812 8 

Some high school 4,342 19 1,239 15 449 18 6,030 18 

High school diploma 11,311 49 3,441 41 1,040 41 15,792 47 

Vocational diploma 1,676 7 249 3 246 10 2,171 6 

Some college 1,482 6 540 6 190 8 2,212 7 

College degree 617 3 188 2 74 3 879 3 

Unspecified 1,897 8 1,820 22 297 12 4,015 12 

Total 22,999 100 8,377 100 2,536 100 33,912 100 

Excluding job title category of office workers. 

2 MSHA size groups are based on the annual average employment of the primary subunit and not on the total employment; hence, MSHA published injury 
statistics by size groups should not be analyzed against these data. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



18 



Table E-8.— Sand and gravel mining 1986 workforce estimates: job title, by principal equipment operated, 1 number of workers 



Job title grouping 2 



Backhoe 
crane 

dragline 
shovel 



Belt 



Dozer 
heavy 
and 
mobile 
equip- 
ment 



Drill 
(under- 
ground) 
rock 
bolter 



Drill 
(surface) 



Explo- 
sives 



Front-end 
loader 

forklift 



Grader 
scraper 



Handtools 
(powered 

and 

non- 
powered) 



Backhoe-crane-dragline-shovel operator 1,199 

Beltman-belt repairman 

Blaster 

Deckhand-barge and dredge operator 3 

Dozer-heavy and mobile equipment operator . . 37 

Driller-rock bolter 

Electrician-lampman 

Front-end loader-forklift operator 

Grader-scraper operator 

Laborer-miner-utility man 

Manager-foreman-supervisor: 

General 80 

Maintenance 3 

Working 

Mechanic-welder-oiler-machinist 

Mine technical support 

Office worker 

Plant operator-warehouseman 

Shuttle car-tram operator 

Truck driver 

Total 



Backhoe-crane-dragline-shovel operator .... 

Beltman-belt repairman 

Blaster 

Deckhand-barge and dredge operator 

Dozer-heavy and mobile equipment operator 

Driller-rock bolter 

Electrician-lampman 

Front-end loader-forklift operator 

Grader-scraper operator 

Laborer-miner-utility man 

Manager-foreman-supervisor: 

General 

Maintenance 

Working 

Mechanic-welder-oiler-machinist 

Mine technical support 

Office worker 

Plant operator-warehouseman 

Shuttle car-tram operator 

Truck driver 

Total 326 

See explanatory notes at end of table. 




194 

7 





20 

11 






15 






3 


1,047 



19 


11 

59 


11 




14 










52 

















27 





147 





5,897 



150 

285 


30 

5 


77 


21 











20 







352 

16 

11 







2 




3 




75 


173 

9 

5 
2,518 


4 





1,323 


247 


1,164 


3 


52 


3 


6,640 


400 


2,787 


Many 


Miscel- 
laneous 


Plant 




Scale-lab 


Shuttle 




Truck 


Welding 


equip- 
ment 


utility 
equip- 
ment 


equip- 
ment 


Pump 


equip- 
ment 
controls 


car 

loco- 
motive 


Truck 
(haulage) 


(utility) 

personnel 

carrier 


machine 
lathe 





28 


21 


























7 


















































75 


734 


5 























21 











110 
















































































16 



































162 


1,630 


304 


184 


14 





16 


74 





155 





271 


27 


11 





72 


98 


16 





























9 





58 











14 


6 


14 























3 


778 








5 





929 





5 


15 

















23 








21 











3,624 





32 


3 


17 


11 




















18 





3 























8.251 









1,733 



5,045 



216 



1,008 



21 



8.501 



232 



808 



19 



Table E-8.— Sand and gravel mining 1986 workforce estimates: job title, by principal equipment operated, 1 number of workers— Con. 



Job title grouping? None Not elsewhere classified 

Backhoe-crane-dragline-shovel operator 4 

Beltman-belt repairman 

Blaster 

Deckhand-barge and dredge operator 28 

Dozer-heavy and mobile equipment operator . . 

Driller-rock bolter 

Electrician-lampman 

Front-end loader-forklift operator 

Grader-scraper operator 

Laborer-miner-utility man 74 17 

Manager-foreman-supervisor: 

General 2,361 

Maintenance 37 

Working 241 

Mechanic-welder-oiler-machinist 

Mine technical support 471 8 

Office worker 3,144 

Plant operator-warehouseman 102 3 

Shuttle car-tram operator 11 

Truck driver 

Total 6,444 57 

1 See appendix B for detailed explanation of equipment operated grouping. 

2 As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Unspecified 



Total 












74 







16 





90 



1,279 

208 

3 

853 

1,381 

56 

75 

5,933 

352 

2,918 

3,466 

40 

387 

3,299 

1,439 

3,188 

3,918 

32 

8,274 



37,100 



Table E-9.— Sand and gravel mining 1986 workforce estimates: job title, by work location at mine, number of workers 



Job title grouping 1 Surface mine Plant or mill 

Backhoe-crane-dragline-shovel operator 1,267 12 

Beltman-belt repairman 156 52 

Blaster 3 

Deckhand-barge and dredge operator 807 45 

Dozer-heavy and mobile equipment operator . . 1 ,360 20 

Driller-rock bolter 56 

Electrician-lampman 62 13 

Front-end loader-forklift operator 5,470 462 

Grader-scraper operator 336 16 

Laborer-miner-utility man 2,434 484 

Manager-foreman-supervisor: 

General 2,582 580 

Maintenance 21 15 

Working 272 91 

Mechanic-welder-oiler-machinist 2,696 604 

Mine technical support 418 110 

Office worker 

Plant operator-warehouseman 1 ,004 2,901 

Shuttle car-tram operator 28 3 

Truck driver 7,657 618 

Total 26,631 6,026 

1 As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Office 



Total 














303 

3 

24 



911 

3,188 

13 







4,443 



1,279 

208 

3 

853 

1,381 

56 

75 

5,933 

352 

2,918 

3,466 

40 

387 

3,299 

1,439 

3,188 

3,918 

32 

8,274 



37,100 



20 



Table E-10.— Sand and gravel mining 1986 workforce estimates: job title, by years of experience at job 



Job title grouping 1 



rx 

to«1 



1< 
t0<2 



2< 

to <3 



3< 

to <5 



5< 

to <10 



1(K 
to«20 



20< 



Unspeci- 
fied 



Total 



Median, 



Backhoe-crane-dragline-shovel operator 253 72 92 137 

Beltman-belt repairman 63 52 14 24 

Blaster 3 

Deckhand-barge and dredge operator 138 107 74 114 

Dozer-heavy and mobile equipment operator . . 280 165 112 112 

Driller-rock bolter 7 3 3 7 

Electrician-lampman 13 16 4 7 

Front-end loader-forklift operator 965 689 679 792 

Grader-scraper operator 66 27 35 54 

Laborer-miner-utility man 1,019 334 316 283 

Manager-foreman-supervisor: 

General 278 21 1 316 347 

Maintenance 4 3 7 

Working 97 22 14 58 

Mechanic-welder-oiler-machinist 716 371 334 359 

Mine technical support 421 162 117 113 

Office worker 486 437 307 262 

Plant operator-warehouseman 749 497 328 550 

Shuttle car-tram operator 3 4 11 

Truck driver 1 ,553 1 ,077 772 957 

Total 7,111 4,249 3,521 4,194 

*As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



281 


268 


140 


36 


1,279 


7 


31 


7 


11 


6 


208 


2 














3 


3 


215 


105 


41 


58 


853 


4 


293 


174 


79 


165 


1,381 


4 


19 


9 





7 


56 


7 


15 


9 


7 


6 


75 


4 


932 


1,063 


379 


433 


5,933 


4 


56 


68 


16 


30 


352 


5 


354 


204 


108 


299 


2,918 


2 


730 


809 


554 


220 


3,466 


9 


7 


3 


16 





40 


9 


70 


76 


34 


17 


387 


5 


665 


424 


152 


279 


3,299 


4 


249 


131 


62 


186 


1,439 


3 


581 


562 


220 


333 


3,188 


5 


767 


523 


192 


313 


3,918 


4 


7 


3 


3 





32 


4 


1,165 


1,008 


379 


1,363 


8,274 


4 



6,436 



5,447 



2,391 



3,751 



37,100 



Table E-1 1 .—Sand and gravel mining 1 986 workforce estimates: job title, by years of experience at company 



J°b title grouping* to^1 to<5 toOO to^S 

Backhoe-crane-dragline-shovel operator 199 297 279 200 

Beltman-belt repairman 43 73 54 3 

Blaster 3 

Deckhand-barge and dredge operator 101 206 270 130 

Dozer-heavy and mobile equipment operator . . 251 444 318 121 

Driller-rock bolter 9 9 22 9 

Electrician-lampman 28 21 16 

Front-end loader-forklift operator 818 1,922 1,148 699 

Grader-scraper operator 89 122 47 63 

Laborer-miner-utility man 1,068 868 453 191 

Manager-foreman-supervisor: 

General 130 751 710 606 

Maintenance 7 12 3 

Working 7 '107 73 44 

Mechanic-welder-oiler-machinist 667 1,100 684 336 

Mine technical support 374 487 268 128 

Office worker 557 982 605 344 

Plant operator-warehouseman 543 1,320 921 517 

Shuttle car-tram operator 14 7 

Truck driver 1,491 2,946 1,360 883 

Total 6,375 11,681 7,247 4,278 

1 As defined by MSHA; see appendix A for detailed explanation of job title grouping 

NOTE— Owing to independent rounding, data may not add to totals shown. 



15< 
to <20 



20< 
to <25 



25< 

to <30 



30< 



Unspeci- 
fied 



Total 



Median, 

v 



118 


61 


56 


64 


5 


1,279 


8 


7 


11 


3 


10 


3 


208 


4 

















3 


3 


35 


40 


14 


19 


37 


853 


7 


102 


50 


7 


19 


70 


1,381 


5 














7 


56 


7 





3 





7 





75 


2 


465 


253 


163 


210 


253 


5,933 


6 


7 


10 


14 








352 


4 


105 


61 


31 


60 


81 


2,918 


3 


436 


198 


283 


245 


107 


3,466 


12 


2 


4 


5 


7 





40 


14 


73 


37 


15 


31 





387 


12 


177 


114 


61 


63 


97 


3,299 


4 


93 


28 


21 


12 


28 


1,439 


3 


241 


116 


81 


88 


174 


3,188 


5 


234 


94 


61 


117 


111 


3,918 


6 


3 


3 





3 





32 


8 


563 


314 


148 


132 


438 


8,274 


4 



2,659 1,397 



964 



1,087 



1,412 



37,100 



Table E-12.— Sand and gravel mining 1986 workforce estimates: job title, by years of mining experience 



21 



J°° title grouping' to°<1 to<5 to?10 to OS 

Backhoe-crane-dragline-shovel operator 113 191 270 186 

Beltman-belt repairman 26 52 62 

Blaster 3 

Deckhand-barge and dredge operator 70 155 243 127 

Dozer-heavy and mobile equipment operator. . 143 225 317 133 

Driller-rock bolter 5 26 9 

Electrician-lampman 12 21 16 11 

Front-end loader-forklift operator 306 1,413 1,107 720 

Grader-scraper operator 37 92 56 67 

Laborer-miner-utility man 834 684 408 147 

Manager-foreman-supervisor: 

General 46 413 522 703 

Maintenance 3 12 3 

Working 35 70 38 

Mechanic-welder-oiler-machinist 368 676 622 350 

Mine technical support 279 339 230 109 

Office worker 350 705 441 245 

Plant operator-warehouseman 295 1 ,124 812 517 

Shuttle car-tram operator 4 7 

Truck driver 909 1,940 1,073 715 

Total 3,788 8,080 6,293 4,079 

1 As defined by MSHA; see appendix A for detailed explanation of job title grouping 

NOTE — Owing to independent rounding, data may not add to totals shown. 



15< 
to <20 



20< 
to<25 



25< 
to «S30 



30< 



Unspeci- 
fied 



Total 



Median, 



155 


98 


73 


92 


101 


1,279 


11 


14 


7 


3 


3 


39 


208 


7 

















3 


3 


51 


24 


32 


13 


139 


853 


8 


135 


88 


21 


22 


296 


1,381 


8 





3 








12 


56 


8 





3 





7 


5 


75 


6 


517 


271 


176 


277 


1,145 


5,933 


9 


7 


7 


14 





74 


352 


6 


123 


58 


23 


60 


581 


2,918 


3 


367 


253 


255 


299 


606 


3,466 


15 


2 


4 


9 


4 


3 


40 


14 


83 


23 


14 


32 


93 


387 


16 


244 


109 


51 


54 


826 


3,299 


7 


65 


18 


18 


14 


367 


1,439 


4 


183 


120 


104 


85 


957 


3,188 


6 


283 


180 


79 


121 


507 


3,918 


7 


3 


3 








14 


32 


10 


415 


211 


144 


116 


2,750 


8,274 


5 



2,649 1,481 1,016 1,199 



8,515 



37,100 



Table E-13.— Sand and gravel mining 1986 workforce estimates: job title, by hours of training received in last 2 years 



Job title grouping 1 



1-8 



9-15 



16 



17-40 41-80 81-160 161 + 



Unspeci- 
fied 



Total 



Mean, 
h 



Backhoe-crane-dragline-shovel operator 220 96 41 222 

Beltman-belt repairman 41 17 3 44 

Blaster 

Deckhand-barge and dredge operator 162 35 18 129 

Dozer-heavy and mobile equipment operator. .315 159 12 143 

Driller-rock bolter 10 4 14 

Electrician-lampman 5 3 7 21 

Front-end loader-forklift operator 1 ,097 583 1 35 807 

Grader-scraper operator 35 11 12 26 

Laborer-miner-utility man 548 207 95 255 

Manager-foreman-supervisor: 

General 736 158 44 468 

Maintenance 6 5 

Working 42 2 12 41 

Mechanic-welder-oiler-machinist 533 227 85 536 

Mine technical support 244 118 48 134 

Office worker 911 131 41 169 

Plant operator-warehouseman 585 306 118 486 

Shuttle car-tram operator 3 3 

Truck driver 1 ,553 580 272 903 

Total 7,043 2,640 943 4,406 

NS Not significant. 

1 As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



157 


64 


41 


34 


404 


1,279 


36 


3 


40 


11 


4 


44 


208 


32 














3 


3 


NS 


127 


79 


37 


21 


244 


853 


38 


111 


78 


28 


28 


507 


1,381 


33 


12 





5 





11 


56 


30 


7 


3 


9 





20 


75 


34 


692 


503 


194 


148 


1,773 


5,933 


35 


45 


42 








181 


352 


29 


204 


284 


82 


90 


1,153 


2,918 


59 


404 


248 


93 


47 


1,267 


3,466 


31 





12 


7 


5 


4 


40 


77 


39 


46 


30 


14 


162 


387 


62 


367 


280 


72 


82 


1,117 


3,299 


36 


174 


147 


28 


39 


508 


1,439 


36 


144 


216 


68 


86 


1,422 


3,188 


39 


633 


347 


117 


141 


1,185 


3,918 


39 


3 


7 








14 


32 


45 


779 


605 


192 


81 


3,309 


8,274 


26 



3,903 3,002 1,015 



819 



13,328 37,100 



36 



22 



Table E-14.— Sand and gravel mining 1986 workforce estimates: job title, by years of age 



Job title grouping 1 



15-20 21-23 24-26 27-29 30-34 35-39 40-49 



50+ 



Unspeci- 
fied 



Total 



Mean, 
V 



Backhoe-crane-dragline-shovel operator 21 26 79 77 

Beltman-belt repairman 3 10 10 31 

Blaster 

Deckhand-barge and dredge operator 9 41 63 96 

Dozer-heavy and mobile equipment operator . . 3 53 132 106 

Driller-rock bolter 5 3 

Electrician-lampman 9 4 4 

Front-end loader-forklitt operator 107 313 559 606 

Grader-scraper operator 5 34 17 

Laborer-miner-utility man 234 430 461 220 

Manager-foreman-supervisor: 

General 40 106 149 

Maintenance 7 

Working 11 3 11 14 

Mechanic-welder-oiler-machinist 88 144 209 325 

Mine technical support 69 112 136 114 

Office worker 131 172 257 202 

Plant operator-warehouseman 51 250 339 394 

Shuttle car-tram operator 14 

Truck driver 117 312 729 754 

Total 853 1,917 3,137 3,122 

NS Not significant. 

1 As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



153 


158 


297 


438 


29 


1,279 


44 


17 


25 


44 


50 


17 


208 


41 














3 


3 


NS 


147 


89 


168 


191 


49 


853 


39 


193 


128 


287 


321 


158 


1,381 


40 


17 





11 


13 


7 


56 


38 


11 


5 


16 


24 


3 


75 


40 


726 


747 


1,123 


1,359 


394 


5,933 


39 


68 


32 


111 


64 


21 


352 


41 


378 


234 


332 


449 


179 


2,918 


34 


366 


537 


853 


1,250 


165 


3,466 


45 


3 


2 


9 


15 


3 


40 


44 


77 


44 


106 


115 


7 


387 


42 


527 


524 


674 


633 


176 


3,299 


39 


201 


170 


237 


342 


59 


1,439 


39 


352 


478 


630 


737 


229 


3,188 


40 


527 


542 


761 


859 


195 


3,918 


39 





3 


3 


11 





32 


42 


1,102 


1,084 


1,552 


1,687 


937 


8,274 


39 



4,866 4,801 



7,213 8,558 



2,633 37,100 



40 



Table E-15.— Sand and gravel mining 1986 workforce estimates: job title, by sex 



Male Female 
Job title g rou P' ln g 1 Workers pct~ Workers 

Backhoe-crane-dragline-shovel operator 1 ,268 4 1 1 

Beltman-belt repairman 208 1 

Blaster 3 

Deckhand-barge and dredge operator 853 3 

Dozer-heavy and mobile equipment operator . . 1 ,370 4 

Driller-rock bolter 56 

Electrician-lampman 75 

Front-end loader-forklift operator 5,876 17 11 

Grader-scraper operator 352 1 

Laborer-miner-utility man 2,851 8 57 

Manager-foreman-supervisor 

General 3,348 1 86 

Maintenance 42 " 

Working 387 1 

Mechanic-welder-oiler-machinist 3,293 1 3 

Mine technical support 906 3 522 

Office worker 1,139 3 2,024 

Plant operator-warehouseman 3,847 1 1 38 

Shuttle car-tram operator 32 

Truck driver 8,182 24 62 

Total 34,088 100 2,814 

1 As defined by MSHA; see appendix A for detailed explanation of job title grouping. 



Unspecified 



Total 



pet 



Workers 



pet 



Workers 



pet 












2 

3 



19 
72 
1 

2 








11 





46 



11 

31 





3 

10 

25 

32 



30 







5 


23 

5 

16 


2 
5 

12 

16 


15 



100 



199 



100 



1,279 

208 

3 

853 

1,381 

56 

75 

5,933 

352 

2.918 

3,466 

42 

387 

3,299 

1,439 

3,188 

3.918 

32 

8,274 



37.101 



3 
1 

2 
4 


16 
1 
8 

9 

1 
9 
4 
9 

11 


22 



100 



NOTE— Owing to independent rounding, data may not add to totals shown. 



Table E-16.— Sand and gravel mining 1986 workforce estimates: job title, by race 



23 



White Black Hispanic 
Job title groupingi Workers pet Workers pet 

Backhoe-crane-dragline-shovel operator 1,118 4 56 3 

Beltman-belt repairman 104 39 2 

Blaster 3 

Deckhand-barge and dredge operator 780 2 61 3 

Dozer-heavy and mobile equipment operator . . 1,118 4 47 3 

Driller-rock bolter 31 

Electrician-lampman 61 

Front-end loader-forklift operator 5,161 16 279 16 

Grader-scraper operator 295 1 

Laborer-miner-utility man 2,015 6 270 15 

Manager-foreman-supervisor: 

General 3,274 10 37 2 

Maintenance 31 

Working 350 1 20 1 

Mechanic-welder-oiler- machinist 2,689 9 140 8 

Mine technical support 1,323 4 34 2 

Office worker 2,973 9 40 2 

Plant operator-warehouseman 3,252 10 266 15 

Shuttle car-tram operator 14 7 

Truck driver 7,024 22 487 27 

Total 31,617 100 1,783 100 2,523 

1 As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Other 



Unspecified 



Total 



Workers 


pet 


Workers 


pet 


Workers 


pet 


Workers 


pet 


80 


3 


12 


3 


13 


2 


1,279 


3 


48 


2 


11 


2 


7 


1 


208 


1 




















3 





11 

















853 


2 


105 


4 


56 


12 


54 


8 


1,381 


4 


21 


1 








3 





56 





7 





3 


1 


4 


1 


75 





340 


13 


85 


18 


67 


9 


5,933 


16 


40 


2 


3 


1 


14 


2 


352 


1 


502 


20 


65 


14 


66 


9 


2,918 


8 


85 


3 


21 


4 


49 


7 


3,466 


9 


5 











4 


1 


40 





7 











11 


2 


387 


1 


363 


14 


56 


12 


52 


7 


3,299 


9 


53 


2 


9 


2 


21 


3 


1,439 


4 


76 


3 


12 


3 


87 


12 


3,188 


9 


293 


12 


73 


16 


33 


5 


3,918 


11 














11 


2 


32 





489 


19 


60 


13 


214 


30 


8,274" 


22 



100 



468 



100 



709 



100 37,100 100 



Table E-17.— Sand and gravel mining 1986 workforce estimates: job title, by education 



Some Some high High school Vocational Some College Unsoecified Total 

Job title grouping 1 elementary school diploma diploma college degree v 

Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet 

Backhoe-crane-dragline-shovel 

operator 181 14 212 17 644 50 91 7 100 8 51 4 1,279 3 

Beltman-belt repairman 28 13 50 24 82 39 13 6 18 8 17 8 208 1 

Blaster 00 00 3 100 00 00 00 00 30 

Deckhand-barge and dredge 

operator 65 8 206 24 478 56 55 6 17 2 7 1 25 3 853 2 

Dozer-heavy and mobile 

equipment operator 161 12 220 16 726 53 65 5 67 5 27 2 115 8 1,381 4 

Driller-rock bolter 9 16 4 6 17 30 5 9 4 6 18 31 56 

Electrician-lampman 3 5 30 39 32 43 3 4 3 5 3 5 75 

Front-end loader-forklift 

operator 471 8 1,068 18 3,023 51 419 7 240 4 81 1 631 11 5,933 16 

Grader-scraper operator 28 8 82 23 163 46 9 2 3 1 67 19 352 1 

Laborer-miner-utility man 487 17 629 22 1,055 36 109 4 109 4 21 1 508 17 2,918 8 

Manager-foreman-supervisor: 

General 111 3 434 13 1,486 43 177 5 581 17 364 11 313 9 3,466 9 

Maintenance 12 29 14 35 7 18 3 9 4 9 40 

Working 11 3 61 16 129 33 18 5 68 18 25 6 75 19 387 1 

Mechanic-welder-oiler- 
machinist 266 8 527 16 1,363 41 372 11 262 8 43 1 467 14 3,299 9 

Mine technical support 21 1 114 8 637 44 88 6 225 16 168 12 187 13 1,439 4 

Office worker 20 1 99 3 1,415 44 164 5 815 26 527 17 149 5 3,188 9 

Plant operator-warehouseman . 358 9 770 20 1,920 49 218 6 187 5 63 2 402 10 3,918 11 

Shuttle car-tram operator 3 11 14 44 7 22 7 23 32 

Truck driver 613 7 1,639 20 4,009 48 492 6 320 4 74 1 1,126 14 8,274 22 

Total 2,831 8 6,129 17 17,207 46 2,335 6 3,027 8 1,406 4 4,164 11 37,100 100 

!As defined by MSHA; see appendix A for detailed explanation of job title grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



24 



Table E-18.— Sand and gravel mining 1986 workforce estimates: 1 principal equipment operated, by years of experience at job 



Equipment operated grouping 2 



rx 
to«1 



1< 
to «2 



2< 

to <3 



3< 

t0<5 



5< 

t0<10 



10< 
to «20 



20< 



Unspeci- 
fied 



Total 



Median, 



Backhoe-crane-dragline-shovel 223 72 90 

Belt 59 54 14 

Dozer-heavy and mobile equipment .... 271 126 98 

Drill (underground)-rock bolter 3 

Drill (surface) 7 3 

Explosives 3 

Front-end loader-forklift 1,078 762 709 

Grader-scraper 77 36 35 

Handtools (powered and nonpowered) . . 634 314 259 

Many equipment 64 16 35 

Miscellaneous utility equipment 708 217 145 

Plant equipment 918 628 458 

Pump 21 16 

Scale-lab equipment-controls 303 109 82 

Shuttle car-locomotive 7 4 

Truck (haulage) 1 ,583 1 ,083 794 

Truck (utility)-personnel carrier 31 3 42 

Welding machine-lathe 159 119 104 

None 421 256 302 

Not elsewhere classified 5 14 

Unspecified 56 11 11 

Total 6,625 3,812 3,214 

1 Excluding job title category of office workers. 

2 See appendix B for detailed explanation of equipment operated grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown 



134 


300 


276 


193 


36 


1,323 


7 


24 


48 


14 


17 


17 


247 


3 


127 


233 


157 


79 


73 


1,164 


5 

















3 


3 


7 


19 


9 





7 


52 


8 

















3 


3 


858 


1,054 


1,213 


428 


537 


6,640 


5 


54 


72 


81 


16 


30 


400 


5 


341 


525 


379 


132 


205 


2,787 


4 


21 


32 


67 


69 


23 


326 


8 


109 


176 


116 


45 


216 


1,733 


2 


749 


1,008 


651 


237 


395 


5,045 


4 


37 


57 


42 


16 


27 


216 


7 


74 


161 


85 


37 


134 


985 


3 





7 


3 








21 


5 


971 


1,217 


1,056 


416 


1,382 


8,501 


4 


28 


41 


14 


30 


21 


211 


4 


48 


180 


80 


34 


83 


808 


3 


342 


697 


639 


416 


227 


3,300 


7 


7 


20 


3 


7 





57 


6 





7 








5 


90 


1 



3,932 



5,856 



4,884 



2,172 



3,417 



33,912 



Table E-19.— Sand and gravel mining 1986 workforce estimates: 1 principal equipment operated, by hours of training 

received in last 2 years 



Equipment operated grouping 2 



1-8 



9-15 



16 



17-40 



41-80 81-160 



161 + 



Unspeci- 
fied 



Total 



Mean, 
h 



Backhoe-crane-dragline-shovel 271 96 37 260 

Belt 37 14 3 41 

Dozer-heavy and mobile equipment ... . 244 95 18 106 

Drill (underground)-rock bolter 

Drill (surface) 10 4 14 

Explosives 

Front-end loader-forklift 1 ,217 629 144 879 

Grader-scraper 67 11 12 26 

Handtools (powered and nonpowered) . . 440 198 99 417 

Many equipment 80 18 5 23 

Miscellaneous utility equipment 310 113 40 183 

Plant equipment 766 374 139 583 

Pump 53 21 21 

Scale-lab equipment-controls 142 106 32 100 

Shuttle car-locomotive 3 3 

Truck (haulage) 1,611 628 272 964 

Truck (utility)-personnel carrier 46 12 57 

Welding machine-lathe 157 58 7 143 

None 647 109 60 424 

Not elsewhere classified 31 5 9 

Unspecified 5 21 7 7 

Total 6,132 2,509 902 4,238 

NS Not significant. 

1 Excluding job title category of office workers. 

2 See appendix B for detailed explanation of equipment operated grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



157 


68 


51 


23 


360 


1.323 


33 


19 


44 


11 


4 


75 


247 


34 


121 


75 


28 


7 


470 


1,164 


27 


3 














3 


24 


9 





5 





11 


52 


30 














3 


3 


NS 


723 


556 


226 


191 


2,074 


6,640 


37 


45 


53 








187 


400 


26 


308 


223 


58 


89 


956 


2,787 


45 


7 


28 


5 


5 


155 


326 


42 


149 


186 


26 


32 


695 


1,733 


35 


775 


477 


202 


208 


1,522 


5.045 


47 


5 


9 


5 





101 


216 


13 


112 


115 


25 


18 


336 


985 


35 


7 


7 











21 


41 


790 


606 


196 


81 


3,354 


8,501 


26 


23 


25 





7 


41 


211 


59 


95 


78 


28 


7 


235 


808 


26 


396 


228 


70 


52 


1,314 


3,300 


32 


9 








3 





57 


28 


7 


7 


11 


7 


18 


90 


121 



3,759 2,786 



947 



733 



11,905 33,912 



35 



25 



Table E-20.— Sand and gravel mining 1986 workforce estimates: 1 principal equipment operated, by years of age 

Mean, 



Equipment operated grouping 2 



15-20 



21-23 24-26 27-29 



30-34 



35-39 



40-49 



50 + 



Unspeci- 
fied 



Total 



Backhoe-crane-dragline-shovel 11 16 83 69 

Belt 3 10 10 31 

Dozer-heavy and mobile equipment .... 3 53 95 100 

Drill (underground)-rock bolter 

Drill (surface) 5 3 

Explosives 

Front-end loader-forklift 128 370 605 618 

Grader-scraper 11 43 22 

Handtools (powered and nonpowered) . . 90 134 184 284 

Many equipment 3 4 35 21 

Miscellaneous utility equipment 195 277 290 160 

Plant equipment 63 293 443 499 

Pump 5 11 5 5 

Scale-lab equipment-controls 35 91 95 70 

Shuttle car-locomotive 3 4 

Truck (haulage) 123 328 739 768 

Truck (utility)-personnel carrier 2 9 19 

Welding machine-lathe 19 35 68 59 

None 39 82 143 170 

Not elsewhere classified 3 12 

Unspecified 3 19 28 7 

Total 722 1 ,745 2,881 2,920~ 

NS Not significant. 

'Excluding job title category of office workers. 

2 See appendix B for detailed explanation of equipment operated grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



144 


161 


319 


481 


40 


1,323 


45 


24 


33 


54 


53 


27 


247 


41 


145 


139 


285 


292 


52 


1,164 


40 








3 








3 


42 


17 





7 


13 


7 


52 


38 














3 


3 


NS 


850 


849 


1,232 


1,489 


500 


6,640 


39 


74 


32 


111 


87 


21 


400 


41 


432 


460 


529 


526 


148 


2,787 


38 


16 


51 


58 


105 


32 


326 


42 


196 


129 


199 


183 


105 


1,733 


32 


749 


630 


953 


1,116 


298 


5,045 


39 


27 


11 


42 


110 





216 


46 


128 


89 


190 


239 


47 


985 


39 





3 


3 


7 





21 


41 


1,127 


1,098 


1,592 


1,789 


937 


8,501 


39 


29 


5 


87 


56 


3 


211 


44 


141 


107 


184 


153 


42 


808 


39 


389 


523 


728 


1,101 


126 


3,300 


44 


14 





7 


21 





57 


42 


14 


4 








14 


90 


26 



4,514 



4,323 



6,583 



7,821 



2,404 33,912 



39 



Table E-21.— Sand and gravel mining 1986 workforce estimates: 1 principal equipment operated, by sex 

- . . » Male 

Equipment operated grouping 2 — — ■ 

Workers pet 

Backhoe-crane-dragline-shovel 1 ,323 4 

Belt 247 1 

Dozer-heavy and mobile equipment .... 1,164 4 

Drill (underground)-rock bolter 3 

Drill (surface) 52 

Explosives 3 

Front-end loader-forklift 6,552 20 

Grader-scraper 400 1 

Handtools (powered and nonpowered) . . 2,781 8 

Many equipment 326 1 

Miscellaneous utility equipment 1 ,672 5 

Plant equipment 4,985 15 

Pump 216 1 

Scale-lab equipment-controls 561 2 

Shuttle car-locomotive 21 

Truck (haulage) 8,405 26 

Truck (utility)-personnel carrier 208 1 

Welding machine-lathe 808 2 

None 3,082 9 

Not elsewhere classified 51 

Unspecified 90 

Total 32,949 100 790 

Excluding job title category of office workers. 

2 See appendix B for detailed explanation of equipment operated grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Female 




Unspecified 


Total 




Workers 


pet 


Workers 


pet 


Workers 


pet 














1,323 


4 














247 


1 














1,164 


3 














3 

















52 

















3 





32 


4 


56 


33 


6,640 


20 














400 


1 


3 





3 


2 


2,787 


8 














326 


1 


51 


6 


11 


6 


1,733 


5 


28 


4 


32 


18 


5,045 


15 














216 


1 


421 


53 


3 


2 


985 


3 














21 





66 


8 


30 


17 


8,501 


25 


3 











211 


1 














808 


2 


181 


23 


38 


22 


3,300 


10 


5 


1 








57 

















90 






100 



174 



100 



33,912 



100 



26 



Table E-22.— Sand and gravel mining 1986 workforce estimates: 1 principal equipment operated, by race 



White Black 

Equipment operated grouping* Wprkers pc< Workers pc{ 

Backhoe-crane-dragline-shovel 1,165 4 56 3 

Belt 143 42 2 

Dozer-heavy and mobile equipment .... 917 3 38 2 

Drill (underground)-rock bolter 3 

Drill (surface) 28 

Explosives 3 

Front-end loader-forklift 5,802 20 320 18 

Grader-scraper 343 1 

Handtools (powered and nonpowered) . . 2,264 8 129 7 

Many equipment 307 1 5 

Miscellaneous utility equipment 1,109 4 154 9 

Plant equipment 4,300 15 301 17 

Pump 201 1 11 1 

Scale-lab equipment-controls 899 3 32 2 

Shuttle car-locomotive 7 3 

Truck (haulage) 7,244 25 490 28 

Truck (utility)-personnel carrier 171 1 14 1 

Welding machine-lathe 641 2 32 2 

None 2,999 10 93 5 

Not elsewhere classified 45 3 

Unspecified 53 18 1 

Total 28,644 100 1 ,742 100 

Excluding job title category of office workers. 

2 See appendix B for detailed explanation of equipment operated grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Hispanic 



Other 



Unspecified 



Total 



Workers 


pet 


Workers 


pet 


Workers 


pet 


Workers 


pet 


77 


3 


12 


3 


13 


2 


1,323 


4 


48 


2 


7 


2 


7 


1 


247 


1 


108 


4 


56 


12 


44 


7 


1,164 


3 




















3 





21 


1 








3 


1 


52 























3 





352 


14 


89 


19 


77 


12 


6,640 


20 


40 


2 


3 


1 


14 


2 


400 


1 


300 


12 


37 


8 


58 


9 


2,787 


8 


14 


1 














326 


1 


376 


15 


51 


11 


44 


7 


1,733 


5 


319 


13 


91 


20 


33 


5 


5,045 


15 














4 


1 


216 


1 


37 


1 


9 


2 


9 


1 


985 


3 














11 


2 


21 





493 


20 


60 


13 


214 


34 


8,501 


25 


19 


1 








7 


1 


211 


1 


103 


4 


23 


5 


9 


1 


808 


2 


114 


5 


18 


4 


76 


12 


3,300 


10 


9 

















57 





19 


1 














90 






2,448 



100 



456 



100 



622 



100 



33,912 



100 



Table E-23.— Sand and gravel mining 1986 workforce estimates: 1 principal equipment operated, by education 

Some Some high High school Vocational Some College iin<;nprifiPfi Trtai 

Equipment operated elementary school diploma diploma college degree uns^mcu 

grouping 2 

Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet 

Backhoe-crane-dragline- 
shovel 206 16 212 16 705 53 49 4 103 8 47 4 1,323 4 

Belt 35 14 55 22 95 38 13 5 14 6 35 14 247 1 

Dozer-heavy and mobile 

equipment 115 10 168 14 610 52 54 5 71 6 27 2 119 10 1,164 3 

Drill (underground)-rock 

bolter 3100 3 

Drill (surface) 9 17 4 7 14 26 5 10 4 7 18 33 52 

Explosives 3100 3 

Front-end loader-forklift 516 8 1,161 17 3,406 51 493 7 289 4 95 1 680 10 6,640 20 

Grader-scraper 28 7 104 26 189 47 9 2 3 1 67 17 400 1 

Handtools (powered and 

nonpowered) 205 7 473 17 1,183 42 322 12 174 6 29 1 402 14 2,787 8 

Many equipment 11 3 85 26 99 30 18 5 33 10 42 13 38 12 326 1 

Miscellaneous utility 

equipment 366 21 383 22 523 30 78 4 67 4 3 314 18 1,733 5 

Plant equipment 442 9 1,005 20 2,529 50 310 6 210 4 100 2 448 9 5.045 15 

Pump 27 12 37 17 106 49 46 21 216 1 

Scale-lab equipment-controls . . 15 2 95 10 482 49 72 7 112 11 46 5 162 16 985 3 

Shuttle car-locomotive 3 16 3 16 733 734 21 

Truck (haulage) 627 7 1,691 20 4,125 49 498 6 357 4 74 1 1,129 13 8,501 25 

Truck (utility)-personnel carrier 11 5 21 10 85 40 9 4 28 13 19 9 38 18 211 1 

Welding machine-lathe 79 10 116 14 282 35 105 13 104 13 26 3 96 12 808 2 

None 118 4 376 11 1,284 39 136 4 616 19 417 13 353 11 3,300 10 

Not elsewhere classified 24 42 26 46 7 12 57 

Unspecified 18 20 43 48 14 15 16 17 90 

Total 2,812 8 6,030 18 15,792 47 2,171 6 2.212 7 879 3 4,015 12 33,912 100 

'Excluding job title category of office workers. 

2 See appendix B for detailed explanation of equipment operated grouping. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



27 



Table E-24.— Sand and gravel mining 1986 workforce estimates: job, company, and mining experience, by work location 



Surface mine Plant or mill 

Experience, yr — — — — - 

Workers pet Workers pet 

At present job: 

0<tO<1 5,051 19 1,257 21 

1<tO<2 2,951 11 711 12 

2< to <3 2,640 10 479 8 

3< to «5 3,056 11 786 13 

5<to«10 4,515 17 1,117 19 

10< to <20 3,845 14 862 14 

20< 1 ,707 6 368 6 

Unspecified 2,865 11 447 7_ 

Total 26,631 100 6,026 100~ 

Median yr. . 4 NAp 4 NAp 

At present company: 

0<tO«1 4,684 18 882 15 

1< to <5 8,599 32 1 ,732 29 

5<tO«10 5,165 19 1,240 21 

10<to«15 2,982 11 820 14 

15<tO«20 1,872 7 449 7 

20< to <25 964 4 264 4 

25<tO<30 629 2 217 4 

30< 725 3 245 4 

Unspecified 1,011 4 176 3_ 

Total 26,631 100 6,026 i00~ 

Median yr. . 5 NAp 7 NAp 

Total mining: 

<Kt0«1 2,726 10 516 9 

1<to<5 5,831 22 1,261 21 

5<to«10 4,624 17 1,074 18 

10<tO«15 2,972 11 759 13 

15<tO«20 1,928 7 446 7 

20< to <25 1 ,080 4 253 4 

25< to <30 743 3 141 2 

30< 887 3 192 3 

Unspecified 5,840 22 1,386 23 

Total 26,631 100 6,026 ToT 

Median yr. . 8 NAp 8 NAp 

NAp Not applicable. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Office 



Total 



Workers 



pet 



Workers 



pet 



803 
586 
403 
352 
805 
740 
316 
439 



18 

13 

9 

8 

18 

17 

7 

10 



4,443 
5 



100 
NAp 



808 
1,350 
842 
475 
338 
169 
118 
117 
225 



18 

30 

19 

11 

8 

4 

3 

3 

5 



4,443 
5 



100 
NAp 



7,111 
4,249 
3,521 
4,194 
6,436 
5,447 
2,391 
3,751 



37,100 
4 



6,375 
11,681 
7,247 
4,278 
2,659 
1,397 
964 
1,087 
1,412 



37,100 
5 



19 
11 

9 
11 
17 
15 

6 
10 

100 
NAp 



17 
31 
20 
12 

7 
4 
3 
3 
4 



100 
NAp 



546 


12 


3,788 


10 


988 


22 


8,080 


22 


595 


13 


6,293 


17 


348 


8 


4,079 


11 


275 


6 


2,649 


7 


147 


3 


1,481 


4 


132 


3 


1,016 


3 


120 


3 


1,199 


3 


1,290 


29 


8,515 


23 


4,443 


100 


37,100 


100 


6 


NAp 


7 


NAp 



Table E-25.— Sand and gravel mining 1986 workforce estimates: training received, by work location 



. . „ Surface mine Plant or mill 

Job training for last 2 yr, h — — ■ — — 

Workers pet Workers pet 

4,998 19 877 15 

1-8 1,879 7 532 9 

9-15 710 3 153 3 

16 3,178 12 930 15 

17-40 2,874 11 773 13 

41-80 2,257 8 435 7 

81-160 764 3 154 3 

161 + 482 2 223 4 

Unspecified 9,490 36 1 ,948 32 

Total 26,631 100 6,026 lOO" 

Mean training h . . 35 NAp 39 NAp 

NAp Not applicable. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Office 



Total 



Workers 


pet 


Workers 


pet 


1,168 


26 


7,043 


19 


229 


5 


2,640 


7 


80 


2 


943 


3 


299 


7 


4,406 


12 


257 


6 


3,903 


11 


310 


7 


3,002 


8 


96 


2 


1,015 


3 


114 


3 


819 


2 


1,889 


43 


13,328 


36 


4,443 


100 


37,100 


100 


37 


NAp 


36 


NAp 



28 



Table E-26.— Sand and gravel mining 1986 workforce estimates: age distribution, by work location 



Surface mine Plant or mill 

Age, yr 

Workers pet Workers pet 

15-20 558 2 118 2 

21-23 1,371 5 293 5 

24-26 2,409 9 389 6 

27-29 2,249 8 596 10 

30-34 3,574 13 803 13 

35-39 3,302 12 853 14 

40-49 5,167 19 1,184 20 

50+ 6,056 23 1 ,416 23 

Unspecified 1,944 7 376 6 

Total 26,631 100 6,026 100~ 

Mean age yr. . 39 NAp 40 NAp 

NAp Not applicable. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Office 



Total 



Workers 


pet 


Workers 


pet 


177 


4 


853 


2 


253 


6 


1,917 


5 


340 


8 


3,137 


8 


278 


6 


3,122 


8 


489 


11 


4,866 


13 


646 


15 


4,801 


13 


862 


19 


7,213 


19 


1,086 


24 


8,558 


23 


313 


7 


2,633 


7 


4,443 


100 


37,100 


100 


40 


NAp 


40 


NAp 



Table E-27.— Sand and gravel mining 1986 workforce estimates: sex, race, and education, by work location 



Sex: 

Male 

Female 

Unspecified 

Total 

Race: 

White 

Black 

Hispanic 

Other 

Unspecified 

Total 

Education level: 

Some elementary 

Some high school 

High school diploma 

Vocational diploma 

Some college 

College degree 

Unspecified 

Total 26,631 



Surface 


mine 


Plant or 


mill 


Office 




Total 




Workers 


pet 


Workers 


pet 


Workers 


pet 


Workers 


pet 


26,338 


99 


5,883 


98 


1,867 


42 


34,088 


92 


204 


1 


69 


1 


2,541 


57 


2,814 


8 


89 





74 


1 


35 


1 


198 


1 


26,631 


100 


6,026 


100 


4,443 


100 


37,100 


100 


22,494 


84 


4,996 


83 


4,127 


93 


31,617 


85 


1,280 


5 


446 


7 


56 


1 


1,783 


5 


1,976 


7 


429 


7 


118 


3 


2,523 


7 


338 


1 


98 


2 


32 


1 


468 


1 


543 


2 


56 


1 


110 


2 


709 


2 


26,631 


100 


6,026 


100 


4,443 


100 


37,100 


100 


2,270 


9 


517 


9 


44 


1 


2,831 


8 


4,784 


18 


1,148 


19 


197 


4 


6,129 


17 


12,282 


46 


2,897 


48 


2,028 


46 


17,207 


46 


1,725 


6 


393 


7 


217 


5 


2,335 


6 


1,671 


6 


332 


6 


1,024 


23 


3.027 


8 


589 


2 


104 


2 


714 


16 


1,406 


4 


3,310 


12 


634 


11 


220 


5 


4,164 


11 



100 



6,026 



100 



4,443 



100 



37,100 



100 



NOTE —Owing to independent rounding, data may not equal to totals shown. 



29 



Table E-28.— Sand and gravel mining 1986 workforce estimates: 1 experience at job, by 

Experience at ^g 9 . 15 16 17 . 40 41 . 80 81-160 
present job, yr 

0< to <1: 

Workers 1,200 808 157 525 841 420 227 

pet 18 12 2 8 13 6 3 

1< to <2: 

Workers 691 280 76 427 507 435 81 

pet 18 7 2 11 13 11 2 

2< to <3: 

Workers 652 269 90 337 386 317 142 

pet 20 8 3 10 12 10 4 

3< to <5: 

Workers 798 335 146 482 363 298 203 

pet 20 9 4 12 9 8 5 

5< to <10: 

Workers 1,168 272 208 1,046 681 515 162 

pet 20 5 4 18 12 9 3 

10< to <20: 

Workers 948 322 153 712 635 406 124 

pet 19 7 3 15 13 8 3 

20<: 

Workers 468 112 26 398 174 219 5 

pet 22 5 1 18 8 10 

Unspecified: 

Workers 207 111 46 311 173 176 3 

pet __6 3 1 £1 5 5 0_ 

Total: ----- 

Workers 6,132 2,509 902 4,238 3,759 2,786 947 

pet 18 7 3 12 11 13 3_ 

NAp Not applicable. 

'Excluding job title category of office workers. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



hours of training received in last 2 years 



161 + 



Unspeci- 
fied 



Total 



Mean, 
h 



159 
2 


2,288 
35 


6,625 
100 


36 
NAp 


118 
3 


1,198 
31 


3,812 
100 


41 
NAp 


132 
4 


889 
28 


3,214 
100 


51 
NAp 


68 

2 


1,239 
32 


3,932 
100 


32 
NAp 


107 
2 


1,696 
29 


5,856 
100 


29 
NAp 


98 
2 


1,486 
30 


4,884 
100 


34 
NAp 


30 

1 


738 
34 


2,172 
100 


27 
NAp 


21 
1 


2,369 
69 


3,417 
100 


33 
NAp 


733 
2 


11,905 
35 


33,912 
100 


35 
NAp 



Table E-29.— Sand and gravel mining 1986 workforce estimates: 

Experience at 15 _ 20 21 _ 23 24 . 26 27 . 29 30.34 35 . 39 
present job, yr 

0< to <1: 

Workers 443 710 960 876 838 633 

pet 7 11 14 13 13 10 

1< to <2: 

Workers 144 310 449 418 687 510 

pet 4 8 12 11 18 13 

2< to <3: 

Workers 53 275 429 321 462 439 

pet 2 9 13 10 14 14 

3< to «5: 

Workers 38 192 418 471 687 679 

pet 1 5 11 12 17 17 

5< to <10: 

Workers 117 416 648 951 842 

pet 2 7 11 16 14 

10< to <20: 

Workers 58 553 835 

pet 1 11 17 

20<: 

Workers 23 

pet 1 

Unspecified 

Workers 44 141 208 127 336 362 

pet _J 4 6 4 10 11 

Total: 

Workers 722 1,745 2,881 2,920 4,514 4,323 

pet 2 5 8 9 13 13 

NAp Not applicable. 

1 Excluding job title category of office workers. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



experience at job, by years of age 



40-49 



50 + 



Unspeci- 
fied 



Total 



Mean, 



955 
14 


775 
12 


434 

7 


6,625 
100 


34 
NAp 


600 
16 


534 
14 


160 
4 


3,812 
100 


35 

NAp 


646 
20 


419 
13 


171 
5 


3,214 
100 


36 

NAp 


777 
20 


580 
15 


90 

2 


3,932 
100 


37 
NAp 


1,225 
21 


1,451 
25 


206 

4 


5,856 
100 


41 
NAp 


1,448 
30 


1,804 
37 


186 
4 


4,884 
100 


46 
NAp 


442 
20 


1,686 
78 


21 
1 


2,172 
100 


55 
NAp 


490 

14 


573 
17 


1,136 
33 


3,417 
100 


40 
NAp 


6,583 
19 


7,821 
23 


2,404 

7 


33,912 
100 


39 
NAp 



30 



Table E-30.— Sand and gravel mining 1986 workforce estimates: 1 experience at job, by sex 

Male Female Unspecified 

Experience at present job, yr — — — — - — — - 

Workers pet Workers pet Workers pet Workers 

(K to <1 6,316 19 270 34 39 22 6,625 

1<tO<2 3,698 11 109 14 5 3 3,812 

2<to<3 3,122 9 87 11 5 3 3,214 

3< to <5 3,825 12 82 10 25 14 3,932 

5<to«10 5,712 17 105 13 39 22 5,856 

10<tO«20 4,811 15 65 8 9 5 4,884 

20< 2,131 6 9 1 32 18 2,172 

Unspecified 3,334 10 62 8 21 12 3,417 

Total 32,949 100 790 TOO 174 100 33,912 

Median yr. . 4 NAp 2 NAp 6 NAp 4 

NAp Not applicable. 

'Excluding job title category of office workers. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Total 



pet 



20 
11 

9 
12 
17 
14 

6 
10 



100 
NAp 



Table E-31.— Sand and gravel mining 1986 workforce estimates: 1 experience at job, by race 



_ . . . White Black Hispanic 

Experience at present job, yr — — — — - 

Workers pet Workers pet Workers 

0<to«1 5,615 20 311 18 516 

1<to<2 3,106 11 185 11 363 

2<to<3 2,650 9 169 10 296 

3<to<5 3,261 11 314 18 305 

5< to <10 4,919 17 368 21 402 

10<tO«20 4,351 15 239 14 234 

20< 1,917 7 102 6 89 

Unspecified 2,825 10 54 3 243 

Total 28,644 100 1,742 100 2,448 

Median yr. . 4 NAp 4 NAp 3 

NAp Not applicable. 

1 Excluding job title category of office workers. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Other 



Unspecified 



Total 



pet 



Workers 



pet 



Workers 



pet 



Workers 



pet 



21 
15 
12 
12 
16 
10 
4 
10 



65 
116 
73 
14 
92 
43 
23 
30 



14 

26 

16 

3 

20 

9 

5 

7 



118 
42 
26 
37 
75 
18 
41 

265 



19 
7 
4 
6 

12 
3 
7 

43 



100 
NAp 



456 
3 



100 
NAp 



622 
3 



100 
NAp 



6,625 
3,812 
3,214 
3,932 
5,856 
4,884 
2,172 
3,417 



33,912 
4 



20 
11 

9 
12 
17 
14 

6 
10 



100 
NAp 



Table E-32.— Sand and gravel mining 1986 workforce estimates: 1 experience at job, by education 

Some Some high High school Vocational Some College UnsDecified 

Experience at elementary school diploma diploma college degree ^ 

present job, yr 

Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet 

0<tO<1 603 21 1,084 18 3,307 21 433 20 446 20 145 16 606 15 

1<to<2 221 8 799 13 1,840 12 263 12 237 11 67 8 386 10 

2<to<3 230 8 646 11 1,597 10 270 12 211 10 55 6 205 5 

3<tO<5 312 11 787 13 2,020 13 306 14 220 10 84 10 202 5 

5<tO<10 471 17 1,059 18 2,660 17 395 18 404 18 200 23 668 17 

10<tO«20 535 19 935 16 2,036 13 310 14 448 20 180 20 440 11 

20< 373 13 417 7 975 6 86 4 91 4 83 9 147 4 

Unspecified 67 2 304 5 1,356 9 109 5 154 7 67 8 1.360 34 

Total 2,812 100 6.030 100 15,792 100 2,171 100 2,212 100 879 100 4,015 100 

Median. . .yr. . 6 NAp 4 NAp 4 NAp 4 NAp 5 NAp 7 NAp 5 NAp 

NAp Not applicable. 

'Excluding job title category of office workers. 

NOTE— Owing to independent rounding, data may not add to totals shown. 



Total 



Workers 


pet 


6,625 


20 


3.812 


11 


3.214 


9 


3,932 


12 


5.856 


17 


4,884 


14 


2,172 


6 


3,417 


10 


33.912 


100 


4 


NAp 



31 



Table E-33.— Sand and gravel mining 1986 workforce estimates: 1 experience at company, by hours of training received in last 2 years 

Experience at n ^.g g.-jg 
present company, yr 

(K to <1: 

Workers 1,149 817 145 

pet 20 14 2 

1< to <5: 

Workers 2,089 867 270 

pet 20 8 3 

5< to <10: 

Workers 1 ,300 317 192 

pet 20 5 3 

10< to <15: 

Workers 619 191 164 

pet 16 5 4 

15< to <20: 

Workers 336 134 46 

pet 14 6 2 

20< to <25: 

Workers 118 57 18 

pet 9 4 1 

25< to <30: 

Workers 157 33 18 

pet 18 4 2 

30<* 

Workers 172 58 20 

pet 17 6 2 

Unspecified: 

Workers 191 35 30 

pet 15 3 2_ 

Total: 

Workers 6,132 2,509 902 

pet 18 7 3 

NAp Not applicable. 

'Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



16 



264 
5 

951 
9 

1,112 
17 

658 
17 

499 
21 

369 
29 

177 
20 

195 
19 

14 
1 



4,238 
12 



17-40 



757 
13 

1,074 
10 

727 

11 

467 
12 

311 

13 

174 
14 

55 
6 

138 
14 

56 

5 



3,759 
11 



41-80 



359 
6 

989 
9 

538 
8 

267 

7 

197 
8 

118 
9 

58 

7 

85 

9 

175 

14 

2,786 
8 



81-160 



188 
3 

376 
4 

233 
4 

70 
2 

50 

2 

19 

1 




5 
1 

5 
0_ 

947 
3 



161 + 



139 
2 

273 
3 

164 
2 

65 
2 

33 

1 

5 


16 
2 

32 
3 

5 
0_ 

733 
2 



Unspeci- 
fied 



1,999 
34 

3,809 
36 

2,059 
31 

1,433 
36 

813 
34 

402 
31 

369 
42 

295 
29 

726 
59 

11,905 
35 



Total 



5,818 
100 

10,698 
100 

6,642 
100 

3,934 
100 

2,418 
100 

1,281 
100 

883 
100 

999 
100 

1,238 
100 

33,912 
100 



Mean, 
h 



35 

NAp 

40 
NAp 

34 
NAp 

32 

NAp 

32 
NAp 

28 

NAp 

35 
NAp 

33 

NAp 

36 

NAp 

35 

NAp 



Table E-34.— Sand and gravel mining 1986 workforce estimates: 1 experience 

Experience at 15 . 20 21 _ 23 24 _ 26 27 . 2g 30 . 34 35 . 3g ^^g 
present company, yr 

0< to <1: 

Workers 428 704 910 755 689 500 748 

pet 7 12 16 13 12 9 13 

1< to <5: 

Workers 256 875 1 ,264 1 ,263 1 ,692 1 ,564 1 ,755 

pet 2 8 12 12 16 15 16 

5< to <10: 

Workers 141 538 751 1 ,248 928 1 ,283 

pet 2 8 11 19 14 19 

10<to<15: 

Workers 99 663 837 1,078 

pet 3 17 21 27 

15< to <20: 

Workers 83 369 857 

pet 3 15 35 

2CK to <25: 

Workers 60 546 

pet 5 43 

25< to <30: 

Workers 195 

pet 22 

30<: 

Workers 24 

pet 2 

Unspecified: 

Workers 37 25 169 51 139 65 97 

pet __3 2 14 4 11 5 8_ 

Total: 

Workers 722 1,745 2,881 2,920 4,514 4,323 6,583 

pet 2 5 8 9 13 13 19^ 

NAp Not applicable. 

1 Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



at company, by years of age 



50+ 



Unspeci- 
fied 



Total 



Mean, 
V 



603 
10 


480 
8 


5,818 
100 


33 
NAp 


1,328 
12 


701 

7 


10,698 
100 


35 
NAp 


1,388 
21 


364 
5 


6,642 
100 


39 
NAp 


1,085 
28 


172 
4 


3,934 
100 


44 
NAp 


1,001 
41 


109 
5 


2,418 
100 


48 
NAp 


672 
52 


4 



1,281 
100 


51 
NAp 


646 
73 


42 
5 


883 
100 


54 
NAp 


961 
96 


14 

1 


999 
100 


54 
NAp 


137 
11 


517 

42 


1,238 

100 


35 

NAp 


7,821 
23 


2,404 

7 


33,912 
100 


39 
NAp 



32 



Table E-35.— Sand and gravel mining 1986 workforce estimates: 

Experience at Male Female 

present company, yr Workers pet ~ "Workers pet 

0< to <1 5,528 17 260 33 

1< to <5 10,355 31 298 38 

5<to«10 6,462 20 137 17 

10< to <15 3,878 12 49 6 

15<t0«20 2,384 7 24 3 

20< to <25 1 ,256 4 3 

25< to <30 864 3 9 1 

30< 999 3 

Unspecified 1,223 4 9 1 

Total 32,949 TOO 790 100 

Median yr . . 5 NAp 3 NAp 

NAp Not applicable. 

1 Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



experience at company, by sex 



Unspecified 



Workers 



pet 



Total 



Workers 



pet 



30 

45 

42 

7 

11 

21 

11 



7 



17 

26 
24 
4 
6 
12 
6 

4 



174 
6 



100 
NAp 



5,818 

10,698 

6,642 

3,934 

2,418 

1,281 

883 

999 

1,238 



33,912 
5 



17 
32 
20 
12 

7 
4 
3 
3 
4 



100 
NAp 



Table E-36.— Sand and gravel mining 1986 workforce estimates: 1 experience at company, by race 



Experience at White Black Hispanic 

present company, yr workers pet "Workers pet Workers 

0< to <1 4,922 17 280 16 434 

1< to <5 8,91 1 31 561 32 921 

5< to <10 5,612 20 327 19 478 

10< to <15 3,425 12 219 13 242 

15<to«20 2,127 7 129 7 130 

20to<25 1,109 4 79 5 62 

25 to « 30 795 3 28 2 33 

30 880 3 63 4 56 

Unspecified 863 3 55 3 92 

Total 28,644 100 1,742 100 2,448 

Median yr. . 6 NAp 6 NAp 4 

NAp Not applicable. 

Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



Other 



Unspecified 



Total 



pet 



Workers 



pet 



Workers 



pet 



Workers 



pet 



18 

38 

20 

10 

5 

3 

1 

2 

4 



84 

168 

119 

31 

26 

9 

9 



11 



18 
37 
26 
7 
6 
2 
2 

2 



98 

138 

106 

16 

7 

21 

18 



218 



16 
22 
17 

3 
1 
3 
3 

35 



100 
NAp 



456 
4 



100 
NAp 



622 
4 



100 

NAp 



5,818 

10,698 

6,642 

3,934 

2.418 

1,281 

883 

999 

1,238 



33,912 
5 



17 
32 
20 

12 

7 
4 
3 
3 
4 



100 
NAp 



Table E-37. — Sand and gravel mining 1986 workforce estimates: 1 experience at company, by education 

Experience at , Som f Some hi 9 h High school Vocational Soml College unspecified Total 

present company elementary school diploma diploma college degree 

yr Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet 

0<tO<1 519 18 994 16 2,787 18 412 19 402 18 70 8 633 16 5.818 17 

1< to <5 746 27 1,934 32 5,432 34 778 36 621 28 211 24 977 24 10,698 32 

5<tO«10 454 16 1,051 17 3,248 21 419 19 435 20 246 28 790 20 6.642 20 

10<to<15 343 12 716 12 1,592 10 268 12 322 15 167 19 526 13 3.934 12 

15<tO«20 243 9 470 8 888 6 133 6 218 10 90 10 378 9 2.418 

20< to <25 181 6 222 4 596 4 20 1 72 3 25 3 165 4 1.281 4 

25<tO<30 127 5 187 3 335 2 3 22 1 53 6 156 4 883 3 

30< 168 6 238 4 410 3 32 1 59 3 18 2 74 2 999 3 

Unspecified 30 1 219 4 506 3 106 5 62 3 316 8 1.238 4 

Total 2,812 100 6,030 100 15,792 100 2.171 100 2,212 100 879 100 4.015 100 33.912 100 

Median. . yr. . 7 NAp 5 NAp 5 NAp 4 NAp 6 NAp 8 NAp 7 NAp 5 NAp 

NAp Not applicable. 

'Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



33 



Table E-38.— Sand and gravel mining 1986 workforce estimates: 1 age, by education 

Some Some high High school Vocational Some College Unspecified Total 

elementary school diploma diploma college degree y 

Age, yr 

Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet Workers pet 

15-20 78 11 168 23 306 42 106 15 55 8 10 1 722 100 

21-23 121 7 325 19 857 49 172 10 128 7 21 1 121 7 1,745 100 

24-26 138 5 357 12 1,742 60 236 8 136 5 73 3 198 7 2,881 100 

27-29 121 4 544 19 1,609 55 183 6 193 7 114 4 155 5 2,920 100 

30-34 229 5 788 17 2,169 48 386 9 390 9 107 2 443 10 4,514 100 

35-39 246 6 577 13 2,031 47 295 7 448 10 194 4 532 12 4,323 100 

40-49 594 9 1,365 21 2,774 42 433 7 427 6 153 2 837 13 6,583 100 

50+ 1,233 16 1,677 21 3,079 39 348 4 371 5 174 2 938 12 7,821 100 

Unspecified 51 2 228 9 1,225 51 12 1 64 3 44 2 780 32 2,404 100 

Total 2,812 8 6,030 18 15,792 47 2,171 (5 2,212 7 879 3 4,015 12 33,912 100 

Mean age... yr.. 45 NAp 41 NAp 38 NAp 37 NAp 38 NAp 40 NAp 42 NAp 39 NAp 

NAp Not applicable. 

1 Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



Table E-39.— Sand and gravel mining 1986 workforce estimates: 1 age, race, and education, by sex 



Male Female 

Workers pet Workers 

Age, yr: 

15-20 683 2 39 

21-23 1,644 5 66 

24-26 2,771 8 104 

27-29 2,836 9 84 

30-34 4,389 13 118 

35-39 4,181 13 100 

40-49 6,411 19 130 

50+ 7,679 23 121 

Unspecified 2,356 7 28 

Total 32,949 100 790 

Mean age yr. . 40 NAp 35 

White 27,849 85 748 

Black 1 ,689 5 1 1 

Hispanic 2,432 7 12 

Other 440 1 16 

Unspecified 538 2 3 

Total 32,949 100 790 

Education level: 

Some elementary 2,800 8 

Some high school .... 5,930 18 95 

High school diploma . . 15,311 46 419 

Vocational diploma ... 2,109 6 46 

Some college 2,058 6 148 

College degree 855 3 14 

Unspecified 3,887 12 68 

Total 32,949 100 790 

NAp Not applicable. 

Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



Unspecified 



Total 



pet 



Workers 



pet 



Workers 



pet 



5 
8 

13 
11 
15 
13 
16 
15 
4 





35 

5 



7 

42 

42 

21 

21 





20 

3 



4 

24 

24 

12 

12 



100 
NAp 



174 
39 



100 
NAp 



95 
1 
2 
2 




47 

42 

3 



81 



100 



174 




12 
53 

6 
19 

2 

9 



12 
5 
63 
16 
7 
11 
60 



100 



174 



27 

24 

2 



47 



100 



7 
3 

36 
9 
4 
6 

34 



100 



722 
1,745 
2,881 
2,920 
4,514 
4,323 
6,583 
7,821 
2,404 



33,912 
39 



28,644 

1,742 

2,448 

456 

622 



33,912 



2,812 
6,030 
15,792 
2,171 
2,212 
879 
4,015 



33,912 



2 

5 

8 

9 

13 

13 

19 

23 

7 



100 
NAp 



84 
5 
7 
1 
2 



100 



8 

18 

47 

6 

7 

3 

12 



100 



34 



Table E-40.— Sand and gravel mining 1986 workforce estimates: 1 age and education, by race 

White Black Hispanic Other Unspecified 

Workers pet Workers pet Workers pet Workers pet Workers pcT 

Age, yr: 

15-20 667 2 19 1 32 1 3 1 

21-23 1,416 5 53 3 217 9 12 3 47 8 

24-26 2,421 8 146 8 243 10 31 7 39 6 

27-29 2,378 8 144 8 333 14 32 7 33 5 

30-34 3,750 13 237 14 412 17 65 14 50 8 

35-39 3,645 13 276 16 317 13 59 13 27 4 

40-49 5,598 20 446 26 350 14 108 24 82 13 

50+ 6,810 24 396 23 424 17 122 27 69 11 

Unspecified 1,959 7 27 2 120 5 23 5 276 44 

Total 28,644 100 1,742 TOO 2,448 100 456 100 622 100 

Mean age yr. . 40 NAp 40 NAp 36 NAp 41 NAp 37 NAp 

Education level: 

Some elementary 1,759 6 419 24 586 24 47 10 

Some high school 4,847 17 494 28 601 25 56 12 33 5 

High school diploma . . 14,255 50 592 34 632 26 250 55 63 10 

Vocational diploma ... 1 ,966 7 88 5 50 2 35 8 32 5 

Some college 2,026 7 44 3 120 5 19 4 3 1 

College degree 839 3 18 1 7 2 16 3 

Unspecified 2,951 10 87 5 459 19 42 9 475 76 

Total 28,644 100 1,742 100 2,448 100 456 100 622 100 

NAp Not applicable. 

'Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



Total 



Workers 


pet 


722 


2 


1,745 


5 


2,881 


8 


2,920 


9 


4,514 


13 


4,323 


13 


6,583 


19 


7,821 


23 


2,404 


7 



33,912 
39 



33,912 



100 
NAp 



2,812 


8 


6,030 


18 


5,792 


47 


2,171 


6 


2,212 


7 


879 


3 


4,015 


12 



100 



Table E-41.— Sand and gravel mining 1986 workforce 

estimates: number of workers and coefficient of variation, by 

employment size class 

Employment size class 1 Workers CV, pet 

1-19 25,200 3~! ~~ 

20-49 9,117 14.1 

50-99 2,444 9.7 

100-249 339 5 7 

All groupings 37,100 3.0 

1 MSHA size groups are based on the annual average employment of the 
primary subunit and not on the total employment; hence, MSHA published 
injury statistics by size groups should not be analyzed against these data. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



Table E-42.— Sand and gravel mining 1986 workforce 

estimates: number of workers and coefficient of variation, by 

job title 

Job title grouping 1 Workers CV, pet 

Backhoe-crane-dragline-shovel operator . .. . 1,279 13.1 

Beltman-belt repairman 208 20.8 

Blaster 3 100.0 

Deckhand-barge and dredge operator 853 7.5 

Dozer-heavy and mobile equipment operator 1,381 13.4 

Driller-rock bolter 56 33.2 

Electrician-lampman 75 21 .0 

Front-end loader-forklift operator 5,933 4.7 

Grader-scraper operator 352 30.5 

Laborer-miner-utility man 2,918 5.7 

Manager-foreman-supervisor: 

General 3.466 2.6 

Maintenance 40 17 3 

Working 387 15.7 

Mechanic-welder-oiler-machinist 3,299 4.4 

Mine technical support 1 ,439 1 3.4 

Office worker 3,188 8.9 

Plant operator-warehouseman 3,918 2.5 

Shuttle car-tram operator 32 42.7 

Truck driver 8,274 9.5 

All groupings 37,100 3.0 

1 As defined by MSHA; see appendix A for detailed explanation of job title 
grouping. 

NOTE — Owing to independent rounding, data may not add to totals shown. 



35 



Table E-43.— Sand and gravel mining 1986 workforce 

estimates: 1 number of workers and coefficient of variation, 

by principal equipment operated 

Equipment operated grouping 2 Workers CV, pet 

Backhoe-crane-dragline-shovel 1,323 10.8 

Belt 247 24.9 

Dozer-heavy and mobile equipment 1,164 8.1 

Drill (underground)-rock bolter 3 100.0 

Drill (surface) 52 37.4 

Explosives 3 100.0 

Front-end loader-forklift 6,640 4.9 

Grader-scraper 400 25.7 

Handtools (powered and nonpowered) 2,787 4.9 

Many equipment 326 20.9 

Miscellaneous utility equipment 1 ,733 9.6 

Plant equipment 5,045 3.7 

Pump 216 18.0 

Scale-lab equipment-controls 985 18.0 

Shuttle car-locomotive 21 48.8 

Truck (haulage) 8,501 9.0 

Truck (utility)-personnel carrier 211 13.5 

Welding machine-lathe 808 1 1 .3 

None 3,300 3.7 

Not elsewhere classified 57 58.1 

Unspecified 90 27.1 

All groupings 33,912 2.6 

Excluding job title category of office workers. 

2 See appendix B for detailed explanation of equipment operated grouping. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



Table E-44.— Sand and gravel mining 1986 workforce 

estimates: number of workers and coefficient of variation, 

by work location 



Work location 


Workers 


CV, pet 


Surface mine 

Plant or mill 

Office 


26,631 
6,026 
4,443 


2.7 
8.3 
8.5 


All groupings 


37,100 


3.0 



NOTE —Owing to independent rounding, data may not add to totals shown. 



Table E-45.— Sand and gravel mining 1986 workforce 

estimates: 1 number of workers and coefficient of variation, 

by experience at job, company, and mining 

Experience, yr Workers CV, pet 

At present job: 

0< to <1 6,625 5.9 

1< to <2 3,812 5.1 

2< to <3 3,214 4.3 

3< to <5 3,932 2.4 

5< to <10 5,856 7.0 

10< to <20 4,884 4.8 

20< 2,172 5.3 

Unspecified 3,417 15.8 

All groupings 33,912 2.6 

At present company: 

0<to<1 5,818 5.1 

1<tO<5 10,698 4.9 

5<tO<10 6,642 5.4 

10<tO«15 3,934 4.0 

15< tO«20 2,418 8.8 

20<to<25 1,281 10.6 

25<tO«30 883 11.1 

30< 999 17.0 

Unspecified 1 ,238 20.9 

All groupings 33,912 2.6 

Total mining: 

<K to «1 3,439 6.6 

1< to <5 7,375 3.6 

5< to <10 5,852 6.4 

10< to <15 3,835 4.0 

15<to<20 2,466 8.3 

20< to <25 1 ,361 1 1 .5 

25<to<30 912 6.3 

30< 1,114 13.8 

Unspecified 7,558 1 1 .8 

All groupings 33,912 2.6 

Excluding job title category of office workers. 

NOTE — Owing to independent rounding, data may not add to totals shown. 



Table E-46.— Sand and gravel mining 1986 workforce 

estimates: 1 number of workers and coefficient of variation, 

by training received 

Job training for last 2 yr, h Workers CV, pet 

6,132 9l) 

1-8 2,509 11.7 

9-15 902 13.0 

16 4,238 8.9 

17-40 3,759 13.5 

41-80 2,786 8.1 

81-160 947 9.6 

161+ 733 5.8 

Unspecified 11 ,905 7.8 

All groupings 33,912 2.6 

Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



36 



Table E-47.— Sand and gravel mining 1986 workforce 

estimates: 1 number of workers and coefficient 

of variation, by age 

Age, yr Workers CV, pet 

15-20 722 Til 

21-23 1,745 10.9 

24-26 2,881 7.0 

27-29 2,920 7.2 

30-34 4,514 4.4 

35-39 4,323 2.4 

40-49 6,583 4.8 

50+ 7,821 4.7 

Unspecified 2,404 16.2 

All groupings 33,912 2.6 

1 Excluding job title category of office workers. 

NOTE —Owing to independent rounding, data may not add to totals shown. 



Table E-48.— Sand and gravel mining 1986 workforce 

estimates: 1 number of workers and coefficient 

of variation, by sex, race, and education 

Workers CV, pet 
Sex: 

Male 32,949 2.6 

Female 790 13.2 

Unspecified 174 32.2 

All groupings 33,912 2.6 

White 28,644 2.8 

Black 1 ,742 9.0 

Hispanic 2,448 8.7 

Other 456 12.4 

Unspecified 622 33.2 

All groupings 33,912 2.6 

Education level: 

Some elementary 2,81 2 11.1 

Some high school 6,030 6.9 

High school diploma 15,792 4.4 

Vocational diploma 2,171 12.8 

Some college 2,212 6.1 

College degree 879 1 1 .2 

Unspecified 4,015 10.8 

All groupings 33,912 2.6 

1 Excluding job title category of office workers. 

NOTE — Owing to independent rounding, data may not add to totals shown. 



37 



APPENDIX F.— MINING INDUSTRY POPULATION SURVEY LETTERS 

AND QUESTIONNAIRE 




United States Department of the Interior 



BUREAU OF MINES 

2401 E STREET, NW. 

WASHINGTON, D.C. 20241 



Dear Mine Manager: 

The Bureau of Mines, U.S. Department of the Interior, is requesting your help 
in conducting a survey of the mining industry. The survey is designed to char- 
acterize the nation's mine-worker population by occupation, job experience, 
training, age, and other factors. These data are necessary to accurately ana- 
lyze the nation's mine accidents. At this time, the information sought by 
this survey cannot be obtained from any other source. 

Your firm was randomly selected to represent firms of a similar size in your 
industry. Although your response to this survey is voluntary, the validity of 
the results depends upon a very high response rate. We urge you, therefore, 
to respond as completely and accurately as possible based upon information 
from your personnel files, management records, or direct response from indi- 
vidual workers at your mine. 

Under no circumstances will the information you provide be identified by 
individual mine, company, or worker. The data will be used for statistical 
purposes only and the results of the survey when analyzed with accident statis- 
tics will be made available to the public in the form of official publications. 

Instructions for completing the survey questionnaire are on the enclosed survey 
form. Questions regarding the survey should be directed to: 



Ms. Shall Butani 

Bureau of Mines 

5629 Minnehaha Avenue South 

Minneapolis, MN 55417 

Telephone: (612) 725-4500 

Thank you for your time and effort. 



(Note: Collect calls regarding 
this survey will be accepted during 
regular business hours, 8:00 a.m. to 
4:00 p.m., Central Time.) 



Sincerely, 



/2tJg*&*L 



/ 1 Director 



Enclosure 




United States Department of the Interior 



BUREAU OF MINES 

2401 E STREET, NW. 

WASHINGTON, D.C. 20241 



Dear Employer: 

Recently, we wrote to you requesting your help in obtaining data for a survey 
for the mining industry. This information will be used to produce the 
characteristics of the nation's mine-worker population in order to analyze the 
nation's mine accident data more accurately. We have not yet received your 
response and have enclosed an additional survey questionnaire in case the 
original was misplaced or did not reach you. 

Because your firm was randomly selected to represent firms of a similar size 
in your industry, we are making every effort to obtain your response to ensure 
a true representation of those firms. Your response is strictly confidential 
and will be used for statistical purposes only. 

If you have any questions, please refer to the instructions on the first page 
of the questionnaire or call collect, Ms. Shail Butani at 612-725-4500. If 
you prefer, you may report your information directly by telephone. A response 
during the next 2 weeks would be great assistance to the survey. 

Thank you for your help and support in the Bureau's effort to characterize the 
mine-worker population. 

Sincerely, 




Enclosure 



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